The problem with that is why should those kids that can behave themselves (which used to not just be 'rich kids') be penalized by being stuck in an environment that has to slow down because half the class didn't hear the teacher the first four times because they choose not to pay attention.

In high school, I just stopped showing up. Classes were going too slow for me and didn't hold my attention. I'm not super intelligent but I do like learning and am fully capable of sitting down and focusing.

One size fits all doesn't work anywhere else, why do we expect it to work with educating children that have nothing in common except their age?