I used to do that too, but in a jokingly way. I was doing the same for myself, and let people do the same about me so I wasn't seeing the harm.
Eventually, I noticed that people hated that (however, I don't remember how) and stop it. It was really difficult because I had trouble to know what I could say or not, but mainly because it was a need, like you.
They stop pointing my flaws, so I guess it was like a fight for them, but I don't know why they hated that so much, for my part I want to know what my flaws are!
Anyway, I think they like me better now…