When I wrote that, I was under the assumption that people would use open-source CPU designs from OpenCore for convenience. With a little help from Xilinx and Altera, it wouldn't be too hard for a government to have the synthesizer detect when an OpenCore design is being used and surreptitiously put a backdoor in. I admit that it would be hard to write software to simultaneously detect a completely unique CPU design is being synthesized, figure out its instruction set and weaknesses, and finally create a hardware backdoor that could circumvent any software written for that device.

As always, there's a tradeoff between cost and security. How many hardware hackers are good enough (or motivated enough) to design their own brand new ISA and CPU design, then bootstrap a compiler and OS for their homemade CPU? Maybe 0.001% of the population, if that.