It seems to me that if everyone has an extra $500, the likely result is rent, etc. rises to compensate, and you wind up with essentially the same social situation just with all the prices offset slightly.
If you give everyone $500 and then take $500 back from most people in taxes that just seems like you're shifting around the conditional evaluation of the necessity of aid to the IRS instead. It's still conditional aid, it's just more obscure how it works.
