I can only speak for myself. The main reason I was playing WoW was because of the dungeon finder. Being in a guild does not help with a particular instance you want to do RIGHT THEN. Guildies are not going to stop whtat they are doing run half way across the world for your benefit. Hell, I couldn't even get my guildies to show up for scheduled events.
If you want to bray /lfg like an *** for an hour, then you might get a group. I am amazed that this game would spend so many years in dev and not have a way to get people together efficiently. Monumental failure. This right now is solo rpg where you see other players running around aimlessly while you pursue your own personal storyline.
No instance finder is only one of the problems, but it is the one that affects me the most. The others are lack of char customization, boring/unoriginal combat animations and lack of replayability. In CoH I played dozens of alts over the years and each char was very different. This game is so story driven that there is zero incentive to replay with an alt.
Even so, with all the negs mentioned, I enjoy the game for what it is and for the huge effort that AN has put into it. To compete with WoW a game has to be brilliant, almost a work of genius. Wow is a hard act to follow. For me, it's onward to GW2 -- but not expecting much from that game either given what I have seen on Utube.