whith this example, @Reyhan, you showed perfectly why it's not fun to have nubs on your team, and why many hosts only accept players of their level. even teams means more fun.
also, if this bullying is an effective strategy, than I don't think it can be blamed. it's a coordinated assault, and it makes a lot of sense in TGs.
All in all, I'd say you are painting things a lot darker than they are, and many of these issues are simply caused by 0AD having a small playerbase, and it having a public lobby, with a public chat. there's good to it, and bad.
of course it is true that smurf accounts should be limited somehow, and that TG should have a rating system, both these things have quite some consensus. (but TG rating should not consider in game scores though, this too has been discussed).
I also think that if the game also had a quick matchup system for 1v1, this would make matters simpler, and be more inviting to many new players.