Why is there no quality bar on ranked?

Just had a team full of Diamond players die fifteen consecutive times from face checking brush. Fifteen. Times. Sometimes even the same brush.

Meanwhile, the ADC and I are at a total loss as to how these players are at Diamond, or what we're supposed to do about this, because they aren't listening to back pings, and they aren't figuring out that they shouldn't be doing that.

This should have been dealt with long ago. The season 4 changes, in particular, allowed too many of these players to succeed with only mechanical skills. Now Diamond is overrun by borderline retards who are lacking basic knowledge.

Fifteen. Fucking. Times.