It's not for doing it once, it's for doing it habitually. So if you quit every other game because it's hurting your precious Kill/Death ratio, you'll get punished.
oh cool, instead of a guy leaving a game and someone rejoining instantly we'll now see people start sitting in corners or not playing when they get pissed. Maybe if I have to go enough at random times like say my parents call me to see something, I can get "punished" sweeeeeet!
Guys seriously, it is not like you quit once and get punished. This is for people who quit CONSTANTLY. I like it