Players don't like being forced to group. That is something that has become clear following the release of World of Warcraft, but is it a good thing for the MMO genre? I think not. Look what has happened to WoW: incredibly rude players, self-serving gameplay, lack of any real sociability (the Dungeon Finder makes it practically impossible to meet new friends), and deserted landscapes. With the release of Cataclysm, there aren't even any group-focused quests anymore. Unless you're raiding, everything can be done alone.
My question is, does the MMO genre need to come full circle and focus again on players playing in groups? I think so. But, the problem is that even if grouping is incentivized, people won't do it. I watched a group of 12 or more people surround a quest mob in WoW, individually competing for its spawn timer rather than simply grouping up and knocking it all out at once. I've watched player after player die repeatedly against an elite mob designed for groups to tackle, apparently refusing to look for help. That is why games that want you to group and want you to be social have to cram it down your goddamn throat. EverQuest and Final Fantasy XI for example.
So start cramming. I'm sick of playing alone.