MS has zero vested interest in caring. If they brake booting for Linux users, how does that hurt them in any meaningful way? Sure they get some press, but is it bad press if most people are never affected by this?
I can tell you that you are wrong. Whatever the company’s flaws, the people in Windows care deeply about compatibility and about not breaking things with updates. I have hours of stories from the trenches, and could probably talk at length about how such a point of view would be suicidal for the Windows business.
I don’t know what went wrong here, and I’m not saying Microsoft is blameless. I am saying that whatever went wrong was NOT due to lack of caring about breaking things, even non-Microsoft stuff sharing the same computer.
In that sense, I don't see your experience as invalidating the statement "MS has zero vested interest in caring"?