Most teachers in a modern classroom do not get to 60, let alone 70, the notable exception being heads! You lose the ability to multi-task essential in a modern classroom.

We will end up with a multitude of people on long term sick leave.

If you retire early you lose a huge slice of your pension, so it's just an idirect way of slashing pensions.

On the other hand to be fair to the government, the pensions situation was being talked about well before the crash.