Some of that seems somewhat strategic. With a junior you might do the same if you’re time pressured, or you might sidebar them in real life or they may come to you and you give more helpful advice.
Any senior dev at these organizations should know to some degree how LLMs work and in my opinion would to some degree, as a self protection mechanism, default to ambiguous vague comments like this. Some of the mentality is “if I have to look at it and solve it why don’t I go ahead and do it anyways vs having you do it” effort choices they’d do regardless of what is producing the PR. I think other parts of it is “why would I train my replacement, there’s no advantage for me here.”
Sidebar? With a junior developer making these mistakes over and over again, they wouldn't even make it past the probationary period in their employment contract.
I guess it depends on how you view and interact with other people. I tend to give people the benefit of the doubt that they’re doing their best to succeed. Why wouldn’t you want to help them as much as you reasonably can, unless they’re actively a terrible person?
As a senior dev or manager, you're responsible for the people you've hired. Their mistakes become your mistakes. If they make the same kind of mistake repeatedly, and aren't able to take responsibility, you will have to clean up after them. They're not able to fulfill their job description and must be let go. That's why the probationary period exists.
Realistically, the issues occurring here are intern-level mistakes where you can take the time to train them, because expectations are low and they're usually not working on production-level software. In a FT position the stakes are higher so things like this get evaluated during the interview. If this were a real person, they wouldn't have gotten an offer at Microsoft.
Yeah, I'm sure 100k comments with "Copilot, please look into this" and "The test cases are still failing" will massively improve these models.