"How are you single??" ..why does this question irk me

I [F31] get a lot of "How are you single?? You're so pretty/sane/have your shit together/etc" type questions on dating sites. I feel like the implied question is "You look great on paper! What's the thing that's wrong with you??" Plus it makes me feel like I should have some one, so why the hell don't I. Thoughts?

EDIT: FWIW, in 10 years of on/off online dating between relationships, I've never actually ended up going on more than one date with someone who said this to me (for whatever reasons)