And yes, it is a tough balance and likely there’s no perfect solution.
Personally I feel there’s three big issues with the current opt-in mechanics. One is what I am talking about: ganking is a little too safe, there should be an escalation mechanism of some sort. (My take is that if you gank, you implicitly agree with me that the game should not be safe, so it should also not be safe for you.)
Another is that currently wardec costs only take into account the size of the target - not the attacker. I feel it should be fairly cheap for a small outfit to wardec a much bigger one. Wardec cost should depend on the relative sizes of the involved parties. This would make it possible for new people entering into PvP to create a target-rich environment and take on bigger prey.
A third issue is corp-hopping to dodge decs. This issue was made worse by the fact that you can dodge into a non-wardec eligible player corp, allowing basically anyone to choose on a day-by-day basis if they want to be involved in one of their wars or not. That’s a little too much opt-out.
EDIT: to also say something positive, I think the wardec eligibility thing has forced “blanket wardec alliances” to let go of a lot of “easy mode prey” and look for other opportunities. My hunch is that there has been a spike up in low-sec gate camping since the mechanic change, because that has become an appealing way to find explosions. I like that. It makes the game a little safer for newbies and pure industrials, yes, but I think that’s is a fine exchange for making lowsec a tad more exciting again. (This is hunch from spending a lot of my time in low sec, not data, obvs. So I might be mistaken.)