I'm not sure what experience anyone in this thread has with grad level research as a student/author, but I can assure you that heads roll over this kind of thing.

A professor's career is built on reputation, and that reputation is as strong as their students' (who do much of the "work" such as it is). It comes down to the professor, but this can be a career-ending moment for those students and I'm quite confident there were some very uncomfortable discussions as a result of this.

I was thinking this too, but I don't believe this is the case, and I feel like it would not be a good idea either.

Most of these people are likely students; this should be a learning moment, but I don't think it is yet grounds for their entire academic career to be crippled by being unable to publish in a top-tier ML venue.

Banned from doing free work?

In many cases authors and reviewers are not the same. In your first two publications to such venues you are not allowed to review yourself and need someone else.

I think consequences are well deserved, but hopefully not on the authors cost (if innocent).

What terrible deeds have you done to outburst so harshly?

It’s an unethical, false choice. The reviewers are not perfectly rational agents that do free work, they have real needs and desires. Shame on ICML for exploiting their desperation.