Honestly, I think some people are caught up in the fact that, well, women aren't as frail or weak as society has said they are. Physically speaking, men aren't giants by comparison unlike what most say, and everyone of all gender identities will very much be different regardless. It's probably people wanting to instill a more confident mindset in women or something.

THAT, BEING, SAID

There's a time and place to discuss such things, and even if you're a muscular man, you can just as easily killed by some random thugs on the street, armed or unarmed, especially if outnumbered. De-escalation and avoidance of conflict, no matter who you are or how strong you are is always preferable, and most masters of martial arts and other self-defense classes will typically encourage this mindset no less.