As for the universal blaming of at fault parental figures, I'm perfectly fine with that.
Although you do raise a point. At least mother was more apologetic when she spoke to me, and did not look at me as though I was naught more than a bitter disappointment. It is not as though one can go against a king's wishes, either.
There's no telling what lies Hela was fed that festered all those long years. Unless we go forth and ask her.