Because how come why?
I’d help them. Jesus said to do to others what you want them to do to you. I try to live by that.
It can be excessively hard. Our first instinct is, "they get what they deserve". What we need to think is, "would I really want them to have that attitude towards me if I were in need?".
Even if they let me down or wouldn’t reciprocate, I'd still do it. Someone has to be the bigger person.