For girls, their crotch is just like another joint. It doesn’t hurt to wedge things into it, just like it doesn’t hurt to wedge something into your armpit, elbow, or knee.
But for guys, it’s a special weakness. They have to protect it, avoid letting things hit it, because if they slip up for even a second, they’re in for a world of pain.
That’s why girls’ bodies are better. They have the advantage, they were born without a weak spot.