The other thing all this does is to create 'work to the rule' teachers. Cookie cutter teachers. The days when kids had to go through grades having different personalities and having to learn to live with them as their teachers is gone.
Also, some teachers have a talent for working with discipline kids or poor achievers. Maybe those students don't end up on the dean's list (or above average standardized test scores), but many do manage to get through school. It's not worth it for those kind of teachers to accept those kids anymore.
Fucked up deal for teacher's who don't get 'advanced' classes, also. It's not a level playing field.