It sounds like what he's really saying is that high strength characters are game breakingly overpowered and need to be nerfed IMMEDIATELY! Maybe cap Strength at 14 or 15 during character creation.
None of my non-strength based characters have been able to throw people around and usually can't even get a successful "Shove" going. It's just a wasted turn so I don't use Shove. I'll throw grease bottles though.
They could nerf Lae'Zel, too, then. Maybe drop her strength to 15 and bump her Con or Dex. (should probably put it into Charisma to be honest. She could use a boost there)
The issue isn't with strength or even the concept of the mechanic, its the implementation. Base 5e doesn't have bonus action shoving. And not on this ridiculous level. And it is super easy to go into stealth right now and 100 percent shove people. Heck, a MAGE HAND, a cantrip that is meant to not harm people, can shove Goblins off cliffs with 100 percent chance. You could beat this game purely through Mage Hand, and only mage hand.
Capping strength would be going at the wrong part of the problem, changing the shove mechanic, which is already homebrew, would be the solution. Making it an action, make it not 100 percent chance with stealth, and make the distance scale with strength and less extreme, and it will be a much more reasonable mechanic and in fact could be a fun bit of homebrew.
Also, personally, Laezel's stat spread is fine. If anything, if I had to move stats around, I'd dump her wisdom and maybe her dex by a few points to give her some intellect so she can be a serviceable Eldritch Knight without the headband, always felt like a better subclass due to what I know about Githyanki fighters.
As it is right now, it is overpowered and is breaking and obsoleting the other systems.
