Earlier quoted context omitted.
You're comparing apples to oranges. Operating system architectures can vary a lot. CPU architecture between Intel and AMD can't vary much since they both target x86. Every vulnerability found with Intel CPUs can and has been tested for against AMD CPUs which is something you simply cannot do with operating systems, and AMD CPUs have been found not to have the same vulnerabilities.
>CPU architecture between Intel and AMD can't vary much since they both target x86 Yes they can. Instruction sets are just that, a bunch of op codes and "things" for a processor to do. How a processor actually performs them is open to implementation.
Implementation matters a lot. Heck, it is WHY there are performance differences between AMD and Intel CPUs.