1. More people play TDM so there is more of a chance of playing against lesser players.
2. Less scorestreaks. Its easier to get bigger scorestreaks in Dom than in TDM.
3. TDM there is only one thing to think about, killing the enemy. In dom you have to think about flag caps, score, positioning, defending flags, etc... Its easier to just concentrate on killing than worrying about any of those other things.
I think it comes down to more of the first one though. More people in the game mode means that you have a higher chance of going against bad players.
The biggest one, IMO, is that you're far less likely to run into a full party in TDM. Gametypes like Domination are filled with parties, and if you're matched with a bunch of other random players against a full, coordinated party, you're probably not going to have fun.
mildare_el_rayo: What's the word I'm looking for, here? "An angsty person who loves to complain." Calad:Squall?