Sometimes I do, sometimes I don't.
I reckon if that's your option for earning income, your life is probably pretty shit - even if they have a roof over their heads, earning money by constantly approaching people and 9 x out of 10 being ignored/told to fuck off/abused.... thats a shite way to live.
If I've some spare change I tend to say 'you don't need to tell me the bullshit, here's £2..'
The thing is it doesn't matter WHAT they say, some people will give, some people won't.
Tell folk you want to buy some clean socks and a cup of tea, you want to score some crack or buy a quart of vodka, or tell them you need the train to see your dying grandma... it makes no difference, they'll decide for themselves if they want to give you money or not.
So give or don't give but stop with the 'oh they'll only spend it on...... insert whichever heinous thing you think is wrong'.
Own it - don't give because you don't want to. This judging what someone else spends what is at that point, their money, not yours is a massive part of whats fucked up with this country.
We're so concerned with who has what and the idea that someone has what they don't deserve or is spending on things they shouldn't have, we're screwing ourselves over and cutting off our noses to spite our faces.
Every single day, money that was once yours goes to pay for something you absolutely won't like, approve of, is illegal, immoral, disgusting. Just worry about what YOU do with it eh!