It is about women’s bodies though, a piercing is a form of body modification.

And yeah, in a world where women’s bodies and attire weren’t policed to an extreme degree it might be the same. But it isn’t. It’s not that there’s some linguistic difference but rather that policing women’s bodies happens in millions of unique ways every day. It does happen in some ways to men too, body weight, height, body fat and hygiene those kinda things. Women are policed for those things too, in addition to a million other factors. And we suffer social consequences for those things in ways men do not. We suffer even if we do meet those expectations, because ownership over our bodies is still being taken.

It would still illicit a similar response of confusion from me if someone said they were “dissappointed so many men were getting nipple piercings”. What is the causal relationship between the speaker and the men in question? Why does the speaker feel entitled to those men’s bodies? It would still be weird and wrong to say that. I hear people making claims about women’s bodies literally every day though, and pretty uncommonly about men’s in the same way.