On the other hand, just because you've had trouble finding a group that plays newer editions of the game well, doesn't mean we all have.
I've played D&D an average of twice a week for 27 years with a few hundred different players, and I've seen good ones and bad ones in all editions, of all ages, all that time.
While my current group is almost all 30-40ish, I've played recently with 10 year olds who role-play better than some of the adults I've played with.
I made no such comment regarding finding a group that plays it well. I've found and enjoyed playing in groups that knew the system(s) like the back of their hand so playing the game has not been an issue. I've played with mixed groups of all ages and walks of life and there is a distinct difference in how people play, most often consistent with their age group and/or to what RPG system they were first introduced. In fact, and incidentally, WotC formerly employed me to DM in their stores, yes, paid to DM. How 'bout that. The younger the new players were, the more video-game/CCG they wanted it to be like. When I first started playing, at 10 years old, I did not have the lack of patience nor instant gratification mindset of today's youth.
I've seen just about everything so I'm a pretty good judge of the trends. WotC would be wise to maintain multiple types of games, a tactical one (based on 4e - Warammer-lite) and role playing one (edition 1-3.5 hybrid).