What is going on, Riot?

In the last two days I've had two ragequitters, a Nunu who sat in fountain for minutes at a time coming out only to ult a random spot, and just now an Ez who would go afk for minutes at a time, an Anivia who was placed top and decided to come mid instead and try to get me killed with his walls, and a Blitz who wished death on his lane partner's mom. Add those six up and you get one of the two demotions I've had in the last 2 days (the other one might conceivably have been from my playing).

And yet I've received no notification that anyone has been punished, and based on their match histories most of them have gone on to find plenty of other matches to potentially troll in. And yet, apart from the Blitz I suppose none of them said anything in chat to hurt my widdle feelings, so I suppose Riot is cool with their conduct. How am I supposed to be assured that the rules are being enforced when I have such a density of crap in my games?