That is my understanding also. It was mostly for people who were around and should know better. He would never do this to a new contributor. Granted, he almost never sees code from new contributors in review. But what he will do is, if there is something egregious from a new contributor, he lights of the maintainer of the system.

example. I don't remember what all system Greg KH is responsible for, but for the sake of argument, lets say USB. You as a new contributor, try to contribute a patch to the USB subsystem. Turns out it is total garbage. For it to get Linus's attention, it has to have gone through review by Greg KH. Linus will light up Greg and only Greg because Greg has been doing this for 20+ years.

Now, do I feel he sometimes goes over board and unprofessional? Yes. But people keep contributing and the thing keeps chugging along.