It's there to punish TK's, TH's although sometimes an admin will take exception to a tk/th and kick the player.
Not too long ago I had punched a team-mate, (low damage, friendly/trollish behaviour), he then reports me, pissed off I gave him a legitimate reason to vote me, (overhead swing, he died), he voted me again and then I got kicked from the server by an admin.
But then last night, I get tked deliberately at the end of a round, unable to report the player and admins ignored it.
So.. I guess its meant to be there to punish players, but its usually down to an admin on the server to determine whether its good enough or not I guess.