Bullying is a very real problem in society - beyond elementary and secondary school, as this article shows. I also agree with your point that you’d think teams would have enough invested in players to not allow this (though calling the Kings a professional franchise, in terms of how their ownership and team management operate is a serious stretch).
That said, I don’t buy the idea that this is why Stauskas’ pro career has been a struggle. It’s not on Cousins that Stauskas has made less than 35% of his 800+ NBA 3-point attempts, most of which occurred away from Sacramento. As a pro player, Nik can’t create offense (83% of his baskets are assisted, and his assist rate is tiny), and can’t defend (generally grades out as one of the worst shooting guards). If he’s not putting the ball in the basket, I’m not sure what he’s for.
Caris, on the other hand, is looking REALLY promising.