I wish I could go back and time and tell Joss Whedon of the terrible mistake he's going to make in Age of Ultron, in the wording of this piece of dialogue. I don't believe it was ever his intention to conflate sterility and monsterhood; Natasha was listing the qualities that would make her a terrible partner in her eyes (having killed a lot of people (monster), not able to have children (sterile)). I find it disingenuous of people to claim that he meant it to be cause and effect - I can't have children which makes me a monster, so that whole discussion is a complete waste of time, IMO. I'm sad that they killed her off because I like the character and sap that I am, I want her to be happy. She didn't get to experience a lot of happiness and in contrast to Tony, her death did not feel organic to me. I'd like to believe that she comes back in some way because the idea of watching a Black Widow movie, knowing how it ultimately turns out, does not excite me.