You can be as insulting as you like if you compare X86 (and X86-64) to SPARC and POWER which is what I assume he is doing here considering he provides operating systems for multiple architectures. We're talking about an architecture that started with the 8086 and despite changes to the underlying microcode architecture, the front end ISA and system interface is still plagued with poorly designed extensions hacked on.

Regarding virtualization, any sharing of resources, particularly at a hardware level is an attack vector if not implemented correctly. Whether or not it is implemented correctly or is exploitable is merely a matter of time and effort as demonstrated here. That is unless mathematically verified, which it isn't and based on the evolved x86 architecture probably isn't possible so it can't be more secure and is unlikely to be as secure. That leaves only less secure.