Berate doesn't mean yell, perhaps?

Semantics, but berate implies an aggressive dressing down or criticism. Yelling -- as in raising a voice -- may be a part of that, or not.

I've definitely caught a verbal beatdown from people that sounded perfectly calm and reasonably quiet the whole time.

I have worked in and known of environments where it became appropriate to yell. You would be right not to work there, but not for the reasons you are implying here.

Care to elaborate?

Sure! I'll elaborate on a few aspects in the hopes of covering what you are asking for:

1. It is appropriate to yell at someone when the immediate safety of yourself or another person is threatened.

2. If you accept (1), then the presence of yelling is a much narrower filter than the presence of conditions under which yelling is appropriate. Due to your stated belief that yelling is never appropriate, you see those filters as equal.

3. With (1), I have given you conditions under which I think it is appropriate to yell at someone. Those conditions are never present at my current place of work. So if, based on only those facts, you were to disqualify my place of work as one where you would work, your filter would be too wide.