Emma isn't Henry's mother

I'm only in late season 2 but I really think this might break the show for me. In season 1 Mary Margaret is rightfully horrified when Emma kidnaps Henry, but now that all the characters have their memory and the questionable fairytale morality in which slaughtering dozens of soldiers is moral but god forbid they hurt george or regina, they of course all accept Emma's claim.

But whilst i understand the character's twisted views it's disturbing the writers seem to just think a birth mother returning and taking a child she never knew or raised is okay. Whatever her crimes in pre or post curse, i have seen nothing that makes Emma anything but a scary kidnapper, taking advantage of Henry's confusion, gaslighting him for an entire season that she believes him, lying about his biological father, doing the entire "cool parent" routine. 99% of Regina's post curse evil is either petty, or trying to stop a dangerous kidnapper and her supporters literally stealing her child. The show doesn't frame it this way, the show basically seems to take the position adoptive parenthood is either illegitimate, or worse, it's negated if a ten year old has a tantrum. It doesn't help that so many characters speak negatively about the foster system etc.