The thing with PVP chat is that you'd get hotheads telling you to go die in a fire or kill yourself or whatnot, but even if you blacklist them, you'll still be in a party with them come the next match. At least with party finder, if you blacklist someone, their name and PF is faded out so you know you want nothing to do with it. PVP matches never gave you that luxury -- although this new team-based option might help.