Since Linus is not actually impolite in this email, I'm just going to ignore that and comment on the main thing he talked about:
Calling things "professional" is just more of the same - trying to enforce some kind of convention on others by trying to claim that it's the only acceptable way.
Being professional is similar to being politically correct. Don't say anything impolite or you'll offend people, don't say anything 'unprofessional' or you'll get fired, don't say anything 'not politically correct' or (in some countries) you'll have the police knocking at your door. That is where it leads and that is why I support his argument.
Additionally, in my experience, the above behavior leads to behind-the-back sneaky and spiteful behavior. People who don't like something xyz is doing, so instead of risking confrontation by telling someone politely that it's annoying / won't work, they'll talk to the manager or get back at someone 3 weeks later.