You're going to get that anywhere you go. Hate to break it to you.
I'm on PC, XBL, PSN and Wii and you meet stupid people all the time.
But if you're bothered by teamwork, good fucking luck finding good teammates on ANY sort of system. Good teammates are a very rare commodity. On PSN you get douches in MAG who want to run ahead and say "Fuck you" to the squad (assholes). Also, is it just me, or does it seem like a lot of people yell for no reason?
I have made a few good friends on PSN though.
I think XBL has such a bad rep because everyone had mics. Yes, there are a lot of young kids on it, but I use the blessed mute button and never hear them again. I will agree, there are a lot of rotten apples on XBL, but I've made many great friends and have known some for two years and have even met some.
I can't speak for the Wii community, since most people don't talk... And the Wii speaks sucks so hard that I just turn off mic volume.
On the PC, good luck trying to find a person who will level grind with you, selfish fucker, I wanna be level 50 in City of Heroes. Whiny bastards.
Anywho, I think I got waaaaayyyy off track. The point is, I would give anything more than one try. I think out of Wii, PSN and XBL, XBL is my favorite, I don't mind paying for it because it's always been very reliable and I've never had any sort of problems.