For me, it highly depends on the context. Our city has a lot of "regulars", you just recognize them after a while. Some are super rude and/or pushy. Some, like the punks, compliment you, ask if you have some money for weed, and if you say no, they wish you a nice day and fuck off.
Thing is, I don't like to be lied to, and if I feel like someone who's asking me for money lies to me, I really don't want to give them money.
The punks got my spare change more than once.