I was really ashamed after I read your answer. I'm still not 100% sure that's the spirit I'm willing to adopt, but there is something to it that feels right. I will think about it.
What about after you give them money and they look down at their hand like "WTF? That's it?" and walk away disgusted (or just stare at you)? Do you judge then?
I'm not making this up to be combative. I use to carry a bunch of coins in a quickly accessible pocket just to give to anyone who asks because I hate having to internally debate it every time. The passive beggars are always fine, but I've had frustrating experiences with the active ones (especially the drunk and mentally disturbed).