My proof threshold is high because anytime you are speaking about taking peoples’ money away from them, you better have a pretty high threshold of justification for that. Hashem gave us free will so that we can decide what to do with the money He blesses us with, and if hopefully to be charitable with it then which charitable causes it should go to. I have so many pet causes and people in need I wish I just had an unlimited supply of money I could give to because I really care about them and I think a load of cash could really help them out.
For the government or anyone else to tell me I should have less resources to give those those people and causes I care about solely because they think they know how to dole it out better than I do is absurd.
I have no problem with government assistance from the aspect of giving to those in need, even if some or many of the recipients may not actually deserve it. My problem with it is that the money has to come from somewhere, and the place it comes from is taxpayers who don’t have very much say in how the money taken out of their wallets gets spent.