Tribal human males were always the first gender to adorn themselves with metals, ink and other items and submit themselves to body modification as a rite of passage
Sigh. Yes, I'm aware of that. Primitive culture, pirates, and all that. I was speaking relatively, and specifically of the culture at the time when I was growing up. As I said in my initial post "Back in my day" men didn't wear earrings. Or the guys that did were trying to be nonconformist, or members of the counterculture. It was seen as gender blending, and that's why it was "shocking". Piercings (and black nail polish) became even more popular in the 70s with glam rock and the punk movement. Now days of course, no one will look twice.
Then for awhile, it was considered okay for a guy to wear ONE earring, and it had to be in his left ear. If it was in the right ear, that was a signal that you were homosexual. Then guys started to wear earrings in both their ears, and that took awhile to gain acceptance.
As I said, I don't care for it, but it doesn't change my life one way or the other.