It's irrelevant. Miners can pay themselves a million Bitcoins with an invalid block today if they want. The reason they don't is the same as the reason they'd mine BIP-110 valid blocks. All that matte...
It's curious how much faith we place in these systems without fully grasping that it’s all just human agreement at the end of the day. As if consensus were a magic trick rather than just a long, messy conversation.