That was the idea of abolishing the 11+ and going for the full comprehensive system. So that the less able kids would benefit from the smarter ones, but from my own personal experience, it just didn't work. The ones that pissed about in class and did fuck all tended to drag everyone else down with them and any decent teachers that existed usually gave up and became nothing more than workers in a factory school system, where kids were placed on one end of a conveyer belt, the same curriculum bottons pressed on each one, and then spat out at the other end when they turned 16.
The 11+ had it's many problems, true, but it was the only hope of self-improvement to those from poorer backgrounds. One of the many problems it had was that poor kids who did pass their 11+ and had a chance of going to grammar school still couldn't because they couldn't afford to. If problems like that were re-addressed and financial support given to these kids, then it would offer more the chance of improving their lives.
Then there's the 11+ itself. If it ever did come back, it would need to be closely regulated and changed. There would also have to be two versions of it. One for academical ability, and the other for practical.
But there probably needs to be a complete overhaul of the education system where all political parties and teachers get together and decide on one workable system. Such a system would then be set in stone and the only difference between the parties policy on it would be how much of the budget they were spending on it. But, sadly, the world just isn't that perfect, is it?

I also fully agree that Gove is a twat.