Not that it wasn't always reactionary indeed, what can one expect from people with life-long sinecures but that they be form the upper class, for the upper class?
I am not so much trying to assign blame for the result (mainly because I think that my voice won't add much to a thread where enough people have informed opinions), I'm trying to think of simple sentences that's aren't a rehash of other things we're saying. I don't believe that a multitude of good reasons dilute an argument, though our psychology sometimes lets that happen.
Another thing for the memespace (and it's a rehash, but not yet in this thread) is that "open legs" aren't what create pregnancies, it's ejaculations that do. I find it so weird that (afaict) every single community has incentive for good sexual education, but 'keep your legs together' is the too common advice.
Spoiler meme-shaped summary :





Blame a man every time an unwanted pregnancy comes up. Every chance you get. Normalize that women don't really need men to ejaculate unsafely to enjoy sex.