These discussions are a lotta fun because CCP, like any other company, sometimes explains their decisions, but those explanations often seem to be light years away from what is apparently, or even obviously, true. So its a big circle jerk of guessing games. (sigh)
Something to consider that I do not think has been brought up is the sheer number of combat vessels in the game compared to mining vessels. Percentage wise I am not sure if access is equivalent or not.
As for CCP reasoning on this, they may reason that for the people who gravitate toward mining, being stuck in a venture but gazing over at the mining barge is going to push the maximum number toward omega. They may have even researched it enough to declare that a hard truth (even if they don’t tell us). The character of combat oriented people is simply different.
One thing I think I can tell you for sure is that they don’t give a damn about balancing mining ship and combat ship access for alphas for the sake of having that balance. The base reasoning for such a move would be cosmetics at worst and consistency at best, but once you start asking the question “How exactly does this increase real world profits for the owners?” you start to realize why this is going nowhere. You need a real good answer for that question, or, you really need a dev enthralled with the idea for some reason. I cannot see either happening. (I could see an EVE player mass strike also having an effect, but it won’t happen just to get alphas more ships).
I may be muddying the waters here but I can suggest two alternate routes to simply giving alphas barges for anyone interested. 1) Considering the relative lack of variety of mining ships, push for and even suggest some new types. One thing that I always thought bizarre was that (at least in my time) there are no race specific true mining vessels with unique traits, if we don’t consider corvettes to be mining vessels (and I don’t). Even increasing the number of ORE mining ships would be cool. Maybe even introduce a vessel that blows up (larger) asteroids into chunks and then you pilot that manually to scoop up or tractor said chunks for reprocessing or sale or something. 2) Rather than just ask for mining barges, combine that with some serious nerfing of the T1 venture. The venture is WAY too good/advanced for its position in the mining vessel line up. That simple fact probably helps explain why alphas cannot get something even better in the barges.