I don't think the author realizes the time*attention triage that happens when your sole corporate responsibility is to manage others. I've noticed a distinct personal trend in "email succinctness" the more people I need to manage.

That said, using good grammar is never a bad thing and depending on the subject matter and relationships between the respective communicators, short-hand can be both a deliberate obfuscation practice and social coding of the intimacy of the respective relationships.