Oh, I fully agree on the ME, but AMD is just the other side of the same coin. You need to look beyond x86 to have any chance of getting away from the security problems and general bugginess of both Intel and AMD.
The simple fact is, the ME just got done being put under the microscope in 2017, and it was found to be swiss cheese. It wasn't even looked into for the previous near-decade it was present on Intel platforms, and for all that time it looked impenetrable / no one cared.
Read that last sentence again. Something can have 0 CVEs published just because none of the "good guys" bothered to try to hack it.
Before assuming the PSP is better "just because it's AMD", wait for the PSP to eventually go under that same microscope. I'm sure at least one critical bug will be found, that's really the nature of having closed-source secret sauce "god-mode" security processors built into your chips.
For what it's worth, I prefer civil discussion to anonymous downvotes, too!