I think a majority of us who love pathfinder love it because of how unique and specialized we can make our characters. That all being said, over the course of the last 1.5 years running my players through an AP, I have really started to hate how every PC tends to only do 1, maybe 2 things in combat.
I think the major culprit is how feats like weapon focus work. Since every PC - minus the wizard - has some major bonuses that applied to only 1 weapon, they rarely try to think outside of using that weapon. Interesting loot was sold off, situationally useful weapons were forgotten in a moment they would have worked, and PCs were functionally terrible outside of their niche (this was probably more of an inexperienced player problem).
So I guess my real hope would be for all weapon or tactic specific feats and the like to apply to wider groups (such as fighter weapon groups), or to be easily swappable (such as a fighter training with a new weapon to swap their weapon focus).