not enough men use it?..

well.. when I look at deodorant bases to make or buy , they are all the same. there is not one for men and one for women.
So....probably nothing.

According to the YouTube channel TL;DR's video on the so called "pink tax", the ingredients are different.

I think women feels better and last longer in college I used guys to save money

Pretty much nothing other than that. Mens deodorants is how the companies think all men should smell, and the same goes with womens. I guess the only difference is that they think women should smell like flowery fucks and men should smell like.... Rubbing alcohol and chili peppery fucks, I have no fucking idea what my deodorant smells like. It's right cocked.

well ones for men and the other is for women

Everything women use costs lot more.

-.- that's like me asking why do apples taste like apples besides the fact that they're apples

Secret, strong enough for a man, but gentle for the woman. Lol

I use a gender-neutral salt crystal

Men's deodorants have the 'for men' qualifier added to the label.