Intent is irrelevant. What matters is that the ME is demonstrably insecure, and can be used to invade systems against the will of their users. Whether Igor's correct is not relevant, as far as I'm concerned.

AMD is just as bad as Intel nowadays, but some of their chipsets are supported in Libreboot (KCMA-D8 motherboard and KGPE-D16)

I have no strong feelings one way or the other, regarding Qubes OS. I'm not convinced that true isolation is possible in software. I believe that hardware-based isolation (having multiple physical systems) is better. I do my computing in very much the style of Qubes, but with multiple physical systems.