> the people who can't handle it just aren't smart themselves.

Don't dismiss everyone who won't put up with that kind of environment as "just not smart". It's a completely unwarranted assumption.

Just a hypothetical: Being verbally abused as a child might make that impossible to take as an adult. That doesn't make you any less smart.

But it doesn't even have to be abuse. There are people who are plenty smart, whose reaction to being yelled at by their boss would be "why should I put up with this?" In fact being smarter might even make that response more likely.