Awesome read, thanks for writing this!
As far as the CPU is concerned. PowerISA has all of the equivalent features to the x86 instruction library. PowerISA based CPU's are used in everything from ATM machines to satellites, and has a long history of development. Game developers know how to code to PowerISA, and I don't personally believe that the instruction set in and of itself will be a limiting factor in games development or third party support.
It may not be as bad as I put it, true, however I think some third party companies use anything as an excuse.