We keep coming back to this and you are still not taking into account how mining in a miasmos is not popular.
This is not strictly about yield, it’s not strictly about afk time. This is about behaviour. And even if everyone in an orca stops being afk, they are still being used more often then actual mining barges.
Yield fixes both problems.
I agree with both comments, but there is some point between current yield and no yield where the use of the orca will drop off significantly.
For a caveat of the following statement, I already understand that AFK mining is a possibility but do not believe it is as wide spread as people say. I also know that, while CCP might have the best estimates, nobody but the person controlling the account knows who is AFK mining.
Now, making the argument for AFK mining. Assuming that
You would need to mine 225k m3 of ore a day. At current Orca rates, that is less than 2-2hour AFK sessions.
If that was all you were going for, you could easily reduce the Orcas yield to 25% of its current rate (about 370m3/min) and, while it would be a 2-5 hour sessions, it would still be doable. I would say 10-15% would probably be the cutoff for when it wouldn’t work as an AFK mining ship.
Again, there are multiple arguments on the table. Depending on which argument you are using, the rebuttal to one may not work for the others.
That particular response was to the AFK mining argument.
I have also already stated that I do not have a solid rebuttal for the role argument other than the ORE skill and ship trees are totally FUBAR when compared to other ships lines so why shouldn’t roles be just as FUBAR compared to other ship lines.
EDIT:
You can see the same role issue with the Porpoise, but nobody is crying to burn that ship to the ground…yet.
I see. It seemed like a rebuttal to the general yield nerf argument.
The discussion started somewhere above about how reducing the yield would increase AFK time, I was building on that.
As I said before, the Porpoise doesn’t have a mining yield high enough to compete with barges, so the main problem that the Orca has doesn’t exist for the Porpoise. The Porpoise doesn’t take over the purpose of the barges.
Sure, the Porpoise does have the other problem of the Orca too: it can AFK mine for a quite a while, but it’s also much more easily ganked than an Orca if the person is AFKing in high sec. And if they’re AFKing outside high sec both ships are easily killed. 
I haven’t had a ship fitting tool in ages, and the simulator is a bit clunky*, but at 1.1k m3/min, a Porpoise is still pretty close to the yield of a barge with a larger hold than a Mack and a comparable tank to a Skiff.
So if left alone while the Orca is nerfed, I could easily see all the Orca pilots shifting to the significantly cheaper Porpoise.
But you brought up another point that I always thought was a stupid argument against the Orca…
Basically you are saying that its ok for the Porpoise to have all the same issues as the Orca because it dies easier. If that is true, then the real argument against the Orca is not that it AFK mines or that it takes away the barges job, its that gankers have to work too hard. I don’t see any reason why ships should be nerfed in this game just so that people can gank them easier.
Like i said, it’s the end user behaviour, not the ship stats itself, that indicates a problem.
If players moved to afk mining in a porpoise, that’s a problem…unless they are getting slaughtered by gankers to the point they don’t want to use them anymore. Then it’s not a problem.
Yeah except it doesnt because it escapes much more easily.
But with a tank comparable to a Skiff, if they are getting ganked in a Porpoise then have nothing better to go to. This would also mean that the real issue is ganking, not the ships miners use.
Skiffs and Porpoise get ganked every day, because greedy AFK’ers that only go for max yield don’t tank them…
The real issue is usage. Yield, afk-ability, gankability and anything else those ships bring to the table is part of that.
To further emphasise: if support ships are more commonly used as mining ships than actual mining ships, it indicates a problem.
First, unless you have numbers from CCP stating this is true, then all you are doing is making a broad generalization about usage and want to nerf a ship based on opinion of what people are using it for.
Second, your statement on usage brings up other role issues that do not specifically get fixed by nerfing drone yield. They would only be indirectly fixed because you make the Orca useless for one of many of those roles.
You can fix AFK ability with hold changes, working directly with that issue and gankability is a poor reason to nerf a ship. That would be like saying that its too tough to gank a freighter compared to a T1 hauler so CCP should nerf freighters until they are equally gankable or they are useless compared to a T1 hauler. And yes, I know this is not a direct comparison, but that is because CCP originally made the Orca to have way too many roles and now it is hard to balance it with any other ship that only has 1 role.
EDIT:
I feel like this was a rushed and kind of ugly post. My intent was to point out that the entire line of Industrial Command ships were originally built with too many roles, and using the roles argument for removing/reducing the drone yield is weak. If you have issues with the roles of the Orca, the true fix is not to change one and leave the rest, the fix is to give the Orca a single role and build around that. If anything, they should break the Orca into many ships or use existing ships that have the same role.
Of course i am. How do you think every such thread starts?
When players feedback to CCP about this ship or that mechanic, they aren’t doing it with CCP’s data.
The orca has one design role, to support mining gangs, which is unaffected (or minimally affected) by a yield nerf. That’s why it is the best way to nerf it.
The role an orca shouldn’t have is to be the mining gang all it’s own.
The afk-ability of the orca is also an issue that should be mitigated but is, again dealt with via a yield nerf.
There really is no neater a solution to all the orcas problems than a yield nerf. And if mining behaviour is to just swap to the porpoise, then that too can take a yield nerf.
The end goal of all of this is that mining ships are used for mining and mining support ships are used for mining support. That is the most important goal here. Nerfing afk-ability is desirable but secondary to ships doing their actual jobs.
Actually it needs a better tank!
BTW Ive been mining since 6pm EvE time on the same 4 rocks of Veld, so I say 
to those who said it wasnt possible to AFK mine for hours.
EDIT: First one just popped there! Time to target a bigger one lol
There is nothing saying that mining yourself is not supporting a mining gang. And depending on the level of nerf, its going to be a pointless role if all you do is turn on boosters and come back when your booster charges run low.
Its going to be hard to remove these without completely removing mining from Orcas, which again is going to make the ship boring as hell to own.
It might be “neater” by being the easiest fix to the “problem” but it is also heavy handed by removing an entire role instead making other ships more attractive.
This is a sandbox game, but if you play with your toys in a way we don’t like, we are going to break them. 
So you must wonder why orcas were used on grid before they got a yield buff?
So you must wonder why the orca wasn’t widely used as a mining ship before the buffs?
Powercreep is bad. The orca is the problem, the orca gets the change.
Edit-
That said there are changes I’d make to the other barges and CCP have said they are rebalancing all mining ships. (come on arbitrator!)
Yep. Because a sandbox still needs to be built with certain meaningful choices to be interesting.
That’s why caracals don’t haul better than industrial ships and battleships aren’t designed to be better tackle than frigates.
CCP could make a polaris frig with 10x freighters cargo hold and they could do it tomorrow, and everyone would want one. But CCP want certain ships to play certain roles.
nope, but when they removed off grid boosting they became a burden for my fleet configuration because I needed so many that didn’t contribute any more than when I had one doing off grid boosting. The mining addition gave them more of a purpose.
Before CCP opened the can of worms, and I already said that the breaking point would be below 10-15% current yield, which I am pretty sure is where they were pre-buff.
I am not saying a yield buff, they already mine more than an Orca. I am thinking more of a tank buff for the Mack and Hulk, something along the lines of them not exploding if you sneeze. If anti-ganking is the reason that people are using an Orca over a barge, then make the barges less gankable.
Last comment was more tongue-in-cheek and not meant to be serious, hence the smiley face.
On that we agree. But I’d like a skiff tank nerf too. So they aren’t all so polarised.