Do you refuse to give money?
Do you only give food/drink?
Do you assume they are on drugs?
Do you think they could be fake beggars?
The above points are popular points as to why as a community majority of people don't support the homelessness.
So I was wondering, is being kind important than being right?
I think being kind/polite is a good thing to be in day to day interactions with people, though being kind doesn't imply you need to hand over your cash.
I think there is a bit of a conflation here between beggars and homeless people too. In order to refuse something you need to be asked in the first place, most homeless people I see in London don't ask for anything*. There are plenty of beggars though and yes most of them are not homeless.
I'd assume most people who choose to sleep on the streets have drug or alcohol issues else they'd not be there for very long and would accept help/temporary shelter and then a progress into getting accommodation.
*for example, there are sheltered areas outside the windows of the furniture shops on Tottenham Court road, every night there are small groups of homeless people laying out cardboard shelters and sleeping bags, I've never been asked for anything from any of them. On the other hand, if I turn the corner, then outside Planet Organic, there is a Romanian man or woman from the same gang, sat opposite the entrance asking everyone who goes past for some money...