I don't think it's the PvPs fault these games suck. I think they are just trying to set themselves apart from WoW. WoW has the PvE market cornered, or at least they appear too. That being said I don't think its fair to blame PvP for the bad MMOs that have come out.
Let’s be honest, MMOs just suck lately. Wait let me rephrase that. We have had over 100 MMOs released in the last 10 years. Let’s just pretend it's 100 for easy math. Not all of those were PvP. In fact PvP centric MMOs seem to be a fad of the last 12-18 months. (EVE being the exception) Of those 100+ MMOs we have less than 8 considered successful and less than 5 that were ground breaking.
EQ, UO, DAoC, EVE, and WoW are the only MMOs talked about when people talk about "new" features. Nearly everything else is a second class citizen.
The bottom line is the VAST majority of MMOs just suck. It's not any one features fault. Developers came into the MMO industry like they did the FPS genre 10 years ago. Doom and Duke Nukem showed you could make money on it so a hundred cheap knock offs showed up for every 1 good game. The trend still continues today with FPS games and it has already begun with MMOs. I think it's time we checked all optimism at the door and expected crap. That doesn't mean accept it though...