Oh yeah?
Splitting up my party is bad.
Stop doing it.
I play Halo to play with friends, and when we go in with 8 and have to worry about one or two of us getting split off to the opposite team, it spoils the play. I'm sure there's some solid reasoning about how splitting parties keeps matchmaking wait times to a minimum, but those of us who play the game don't care.
When a party gets split up, one of two things happen:
a) People ninja drop to force matchmaking to abort the game.
b) The people who got split off spend the entire game sabotaging whatever poor schmucks they got teamed with.
Neither case is fun, and we play the game to have fun. If we want to, let us spin our tires waiting an eternity for a game instead of forcing us to team up with people we don't know, and probably do not like. If I want to shoot my friends, well, that's what custom games are for.