I don't see an overall good in the professor's late policy. Awkwardness is usually enough of a deterrent to people willingly being late. This extreme policy punishes those who are unwillingly late (car trouble, emergencies, etc.).

Making a show out of kicking out late students is self-important. The professor extrapolating from this one event that the student is failing at life and should be thankful this professor set him straight indicates more of that attitude to me.

I've been in classes where a late student was told to leave. It was way more distracting than if he'd just been allowed to sit down because it sets off a bunch of pondering and empathy, and you look around you to see what the other students think about the situation, and you're no longer hearing the teacher talk.