Why was the question closed?
Because the question did not demonstrate the notability described in the answers to your previous meta-question
You did not quote a statement from someone that you were skeptical about.
I mean do poor people tend to have poorer kids?
Do you doubt this claim? Is anyone making the opposite claim? If not, it is out-of-scope.
Why was the question deleted?
I wasn't the one who took the action, but I would hazard: It is because when you were challenged to provide notability, instead you took pot-shots at the moderators and added (somewhat distressing) photographs of poverty - these were completely irrelevant to the question - no-one is denying serious poverty exists. The question appeared irredeemable.
Why wasn't the same-sex parents question closed?
Because it was such a notable claim, that everyone involved had heard some variant of it (e.g. "A child needs a mother and a father." or Ref) and the author was (quite reasonably) skeptical about that claim.
p.s. If you do add images, don't forget to provide references.