For beginners I like to teach hitting the high pitch with a level swing first and then add tilt to hit the low pitch but wouldn't it make sense to focus on the low pitch for advanced hitters?
Pitchers are all told to keep the ball down and most pitches will be there. Mike trout is famous for golfing the low pitch out of the park and even though he struggles against hard stuff up he is the best hitter because Pitchers can't exploit it. It seems to be hard to live consistently up in the zone.
Also umpires at higher levels often have a hard time calling higher strikes.
So wouldn't it make sense to focus on hitting the low pitch and try to stay away from higher pitches if possible?