I'd much rather reverse engineer proprietary hardware; I get to have fun doing that and I get to play the upstreaming game better than any of those companies that "support open source" that you love so much (have you seen the mess AMD made? They have hundreds of megabytes of autogenerated headers in the Linux tree now!), while working with a team of motivated and experienced developers and working to make everyone's life as pleasant as possible, minimizing churn, red tape, and inefficiency.
Seriously, there's no way I'd be half as happy working at Intel on Linux drivers as I am working on the M1. And it's not like they support external developers either - most of the chip documentation for Intel/AMD stuff is not public. You can't actually build working graphics drivers from their public docs, not even remotely close. Heck, I had to reverse engineer AMD's GPU microcode to get the variant in the PS4 to work. Totally undocumented stuff.