Earlier quoted context omitted.
At risk of missing sarcasm, a large reason all these vulnerabilities in Intel are found is their market share. Same as when OSX was considered "unhackable" - it just wasn't worth the effort. AMD is likely just as bad, but it's not uncovered (yet). Supporting the underdog is a good idea nonetheless, but not for this reason per se.
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.
Completely and utterly false. The exploits being found exist at a point much lower than the x86 instruction set. ARM processors were also hit with speculative execution exploits.