Live and Learn
everyone knows what the Captain’s authority is so don’t be a smartass
The fact of the matter is that this one was so full of self importance as to come out and face, i.e. confront, the passengers like some kind of power trip jerk that everyone noticed.
99.9% of Captains make announcements from the cockpit and are polite about it, and boarding announcements both automated or by FAs state the requirements to follow crewmember instructions.