Am I weird or is she weird?

Lacks context to really have a clue. I mean, maybe her parents are about to divorce or she has second thoughts about her partner's commitment or whatever and she projected it onto you.

Having said that without any context it's also possible that she got very frustrated because your viewpoint is very common nowadays. And whereas it's pretty obvious that parents should split if there's a toxic home environment, it is also clear that kids suffer bad consequences from divorce and that many people also split because "the spark is gone" etc. So my guess would be that this tends to enfuriate your friend who finds it selfish and short-sighted etc, and when you as her friend expressed that you also feel this way, you became their spokesperson in her eyes more or less.

If you look around here you see a lot of people projecting stuff onto others ("let me guess, you're the type of loose slut/bitter virgin who...") because it feels good being able to pretend that the very archetype of the person you hate is reading it and you can finally get your shot in. While the real emotion is not aimed towards individual opinions or people, but towards how popular a certain way of thinking is.
My two cents.

>>18637785
Dunno the background of the girl but it's possible her parents divorced and it affected her. My parents divorced and had a whole bunch of issues that I swear to never repeat and that likely makes me stubborn on it.

She's probably really passionate about the issue. It's also possible that the way you spoke to her came off as snarky or as a wise ass. It's impossible to really know. You can't expect every topic to be taken lightly or as easy to let go as debating pepsi vs coke or some other pointless bullshit.