re: Why hasn't the under hand freethrow shot ever caught on?

Its not because it looks gay.

Shaq looked far more gay trying to shoot regular free throws. Being embarrassed is looking gay to NBA players.

Almost like a baseball player they are worried it messes with their shot and more difficult...is a specific skill to master apart from their regular game and most players want to concentrate only on their game and not this weird skill.

It's something they've never done. It's scary and weird and takes time to master. You have to invest in it...NBA players aren't willing to do it.

No one ever forces them to do it. Even Shaq. So it's seen as not accepted.

But coaches allowed Shaq to get hacked and for him to look like a clown at the free throw line. What could have been if he had gotten real FT instruction. Obviously he was a lost cause in the normal method and people joked about him...he should have done Barry/Wilt. That's a failure on his teams.