It is correct and helpful because it can prevent continued poor behavior which impacts others. Trying to protect someone's feelings only goes so far. Sometimes you have to be straight and to the point with people whether they take it as a personal attack and it hurts their feelings or not.

Whether it would be appropriate in this I case I don't know but I disagree that it is never the correct response.

> it can prevent continued poor behavior which impacts others

I highly doubt that it would do anything to prevent that continued behavior. I cannot imagine a situation in which there is not a better and more appropriate solution to mitigating poor behavior that telling people "don't participate in this field". At best you will alienate them in such a manner that alternative approaches are less feasible and at worst you convert bad behavior from being passively to actively malicious. I'd be curious if you have a concrete example for when you think this approach has been beneficial in any context.

Note, I consider revoking credentials (e.g. disbarring an attorney or revoking a medical/engineering license) to be something entirely different as there is an active endorsement that needs to be terminated. Relevancy in this case would be to removing a package from a package/dependency listing service/manager.

This is just your opinion, and not a fact or some kind of social rule. In fact, I would say that using your logic, I can say that you should never ever express your opinion on such matters again, since you clearly don't know what you are talking about. Just giving it to you straight. My opinion is fact. Respect it! Do you see the irony?