not sure i would support punishment, however what they definitely need to fix is how slow the matchmaking takes to refill those empty slots. this is what is happening sometimes:
4 to 8 people leave a team
snowballing effect either begins or is worsened
the game takes a while to refill these slots
the other team runs away with the game, the round is unsalvageable
the matchmaking is a little bit odd, ive noticed that when it does refill these slots it does it all at once, almost as if it gets flipped on all of a sudden after a period of inactivity, rather than immediately finding players as they become available