You're prolly correct....
BUT, given 30 years of watching tennis, and that mostly includes player's just starting out, NOT Laver, Barrasetchi, or Chang, there is a definete noticeable trend here.
Shorter player's DON'T hit as hard serves as tall players, and don't need to.
They win with defense and consistency, NOT with huge service winners.
Maybe you should do some positive thinking on your own, instead of just negatively reacting to everything your read.
And try some practical experience applications. Go to a tennis court, look at beginner's learning a conti grip serve, and what do you see?
You obviously never looked.