It's worse on public team games where people refuse to switch team's when it's 3v5 just to get a win stat.

It's gone so far as I've actually seen 1v5 where the other team just racks up the flags and says "oh it'll be over soon"

I mean wtf?

haha, were you the 1?

Defiantly :(

just dont play public :(

Welcome to quakelive?

In the Counter Strike Source days, Auto Team Balance would kick in and move people around.
Best advice I can give is simply don't let it get to you. Stats mean nothing, if they are playing with extra players, they are not getting any better, you don't learn when you are not being challenged. If they care about stats more than a fun game, let them enjoy their free win, if you let it get to you, you're at their level.