so they don't care about users, they care about themself?

I think a more accurate statement is that they don’t want to take on the outsized burden relative to the number of users it would actually affect.

I’d love to dual boot Linux too but I’m under no delusions about being a very small segment of the Mac population.

Apple's whole thing is hardware + software working together. Endless other options available to Linux users. They'd also need to be prepared for people bringing laptops to stores with hardware problems that aren't running macOS. Again, more burden for Apple for no gain other than winning over a couple of dozen users.