Indeed. This is what the people at less wrong mean when they talk about "semantic stop signs". Words to make you stop thinking, and accept the argument as given:

"Some people are dominant destructive bosses because of genetics, m'kay?"

The whole argument falls apart when you realize the author, and nobody really, understands the relationship between your behavior and your genetics enough to conclude anything at all.

I thought the explanations described childhood outcomes that encouraged the tendencies?

Those certainly create a nice narrative.

You think that domineering, alpha, type A people are not more or less born that way?

Nature vs. Nurture is very much not a settled argument. Although if anything, recent understanding in epigenetics movers the needle a bit more in the "nurture" direction.

The interaction surface between genetics and physiology itself is very complex and not well understood. The interaction surface between physiology and behavior is just as complex and not well understood.

It's not that we will never find any gene that affects behavior. We have, and we will. But to draw any big picture conclusion outside the scope of those specific findings is wild and decades if not centuries early.