Most maintainers are volunteer, meaning that they spend their evenings, weekends and holidays developing the kernel because they like it, it gives them a sense of worth and fulfillment that can be hard to come across.

I don't know if you've ever talked to one, but they take a real pride in their work, most make a pitiful salary in comparison to FAANG levels but they still do it because it is full of interesting challenges you can't find anywhere else.

UMN broke that trust. No one is asking the departements to close least of all the maintainers, but you have to understand that kernel devs are not a faceless machine. They spend their limited time on something that is used to make a prodigious amount of money, while never really getting any. In that context they are more than within their rights to be livid.