There is zero relevant constituency for austerity. There is zero mass appetite to curb debt, deficit and spending. This is the reason why with one of the slimmest majorities in recent memory, the House was still able to pass the bill. We live in the age of political patronage. Trump wants to reward his supporters and punish his enemies. This is completely agreeable and understandable. The specifics of the bill can be debated, but the idea of it is correct.
And for those like Massie whining that all of these issues should be voted on separately, it's all a grift. Instead of grandstanding and voting no on one bill, they could grandstand and vote no on 50 bills. Think of the donations!