Just because there's a gap doesn't mean someone is being discriminated against. Shorter men could have self esteem issues that cause them to perform a little worse or fight for salary a little worse.
I worked in sales for a decade. I was better than top 1% at it nationwide. I'm 6'4". Was that because people just love buying from a tall person, or was it because I felt comfortable walking up to anyone and everyone since I was taller than them?
If that were true, you'd have to explain how they got the self-esteem issues in the first place if there wasn't discrimination.
FWIW, I have known a lot of people in sales and it's not confidence that makes you good - that's just a stereotype - but the ability to make the other person feel like you have their interest in mind. Sure you have to be willing to approach someone but without the ability to establish a connection, the confidence would be misplaced. It also seems like anyone can train themselves out of cold call anxiety.
I worked in sales for a decade. I was better than top 1% at it nationwide. I'm 6'4". Was that because people just love buying from a tall person, or was it because I felt comfortable walking up to anyone and everyone since I was taller than them?