>Bras serve a much bigger purpose than covering nipples (hint - what's a jock strap used for? imagine needing that all day, not just when you're running...)

This doesn't work. Jockstraps were designed for protection a century and a half ago with mostly flawed logic. Today they're mostly used to hold protective cups and not for support.

You'll find the vast majority of men that have played sports in school or pursue an athletic sport as an adult have never owned or worn a jock strap. A properly restrictive sports bra would be the female equivalent and will make a world of difference.

I can run flat out and don't care one bit about my genitals flopping around, my 'moobs' however flop around considerably and in a jarring fashion which actually causes pain and they are considerably smaller than many women's breasts. Watch a woman running with an adequate sports bra, you'll see minimal movement of 2 pieces of tissue wearing considerably more than any man's genitals.

Hi, I'm a woman. #1 is definitely the more likely scenario, based on conversations I've had with other women without large breasts. The only people who like wearing bras are people who feel like they need support for whatever reason. For everyone else, they are complicated nipple covers that you are expected by society to wear.

I'm a man, but this reflects what I hear from women too. Those with larger breast really appreciate the support from a bra. Those with smaller breasts mostly prefer not wearing them (from a physical comfort perspective at least).