I think that is important to note as well. His email normally gets the attention when he is pissed off. But the majority of them aren't.

It shows how angry he is, and how he is upset with the issues. While this could be avoided in a real world scenario, I would have bet if your manager feel something strongly about, they would have went rampant as well. And this is especially in remote working, words are hard to get feeling across without putting some "adjectives" into it.