Deriding people based on their height is wrong. But preference for tall males is based on a preference for strength, athleticism, and ability to fight. This is true in all human cultures. If you think it's outdated, consider sports. Almost all MLB pitchers are > 6' and that's not even getting into basketball. In terms of fighting, although stature is less relevant than ever, there are plenty of ongoing military conflicts.

This is true for lots of things. Being fast is better than being slow. Being smart is better than people simple. Being attractive is better than being ugly. Being fit is better than being fat. This isn't a happy realization but it's true and it's healthy to accept it.

The dimension along which all people are equal is a metaphysical or religious dimension, not an empirical one.