I think the current matchmaking is exactly the opposite of what it should be:
you should be able to repeat playing with the party you have won with and hence the people you like instead of repeating to lose over and over with a band of useless clowns not cooperating.
in other words, dissolve the party after a lost round (at least ask if you want to stay or not), but keep the party as is and move on to the next round after a win (and again, ask if you want to stay or not, of course) ...
what do you guys think?