I mostly tend only help if it's asked for, for that reason (as long as it's not a situation where they're in immediate danger or trouble). I guess some people see being offered or accepting help as a weakness in themselves and lash out to try and show strength. So I'm in the same group as you now!
I also try to thank people for help even if I didn't need it, because they're only trying to be kind and I know it can hurt to have it thrown back in your face.