Memes

I've heard the argument based not on structural power but average physical capabilities and biological structures. [I'm going to use the terms meaning sex and not gender]. The man is most likely the person that can gain control during the act, and he doesn't risk being in pain as much as the woman. Therefore, the man holds more power and is more of a threat on average.

This is also technically true, and I don't think it is about consent but freedom. [I'll keep using the words for sex and not gender]. Sexuality becomes another form in which women can become subjugated, so it's a matter of precaution, I guess (especially since men are being socialized to be entitled or even violent, which is the other part of the picture).

I've also heard the extreme version of this argument saying that penetration is what I just described, always, without exception.

In both cases and in yours and in others, I don't think the meme is correct because the reasons are very different from puritanism.