It might be a case of the squeaky wheel, or so one hopes, at least. MMOs could certainly do more to display result of player action in the world, like monuments perhaps. The first group on the server to kill the evil King Teapot, remembered forever. But an MMO game ought to make it very clear that it is less "Look what I did!", and more towards "Look what we did!". Pretending that every character is the special hero (and making thus sure that no one is) is a terribly blunt tool. If anything, I find that it rather increases the feeling of having no significance, but that is a matter of individual taste.
Some of the most fun I had in WoW was PVE instances, which are very easy to queue for and never take very long to put you in an instance with other people. It's really easy to actually interact with other people in that game, to this day I've not played an MMO that got the "multiplayer" part as down pat as WoW.
I wish STO was anywhere near that active. The most people I see queued for an instance is 4... when the smallest ones take at least 20. Except for zone chat it might as well be single player, since all the missions take place in private instances. It's always kind of freaky to go to Earth Starbase and actually see other players.
Instance-diving is rather fun. But I must admit that the instant dungeon system did come at a cost, when it was all reduced to pressing a button and then roll your thumbs for a little while. Believe you me, nothing is worse for a healer than
that group, the one that is in such a hurry that you get the impression that they are on a crashing aeroplane, and just want a few more dungeons done before they die. No time to talk, no time to drink, run, run, run.
It is still an excellent experience, the humble WoW dungeon, when the group is right. It is pretty damned good, actually. It is interaction and co-operation in a simple, pleasant package.
However, one other problem came along with Garrisons, in my mind. Everyone only sitting around in the capital waiting for dungeons to pop up is bad enough, but then everyone got a private instance to sit around in, instead. After that, one wonders if there is even a point in having an overworld after that. Why bother, give the player character a nice, upgradable house and fill the game with dungeons and raids. The only people out in the overworld where either levelling between the dungeon pop-ups or the odd roleplayers who did anything outside the cities (which is reason enough for Blizzard to scrap it, no doubt, for God forbid that they ever give the roleplayers something pleasant). It is a terrible shame, and it does take a lot of scope from the world. Player convenience is very important, but it can easily go too far.