Windows 11 requires a hardware TPM (Trusted Platform Module), which is a black box for crypto key storage. They want to be able to lock you out of certain things on your computer. The nanny processors (IME for Intel, PSP for AMD) and TPM in conjunction with HDCP standards can control whether or not you can view certain media, when used in concert.

The end goal of major tech companies is to limit your freedoms on computing machines. You do things their way or not at all.

Requiring a TPM is a pernicious requirement added for political reasons. When Windows 11 adoption remains crawling, they will suddenly realize "oh you really don't need a TPM for Win11 guys, try it out! :)" to fool people into switching over.

We need more players like Purism and Pine64 who are trying to wrest control of the hardware layer away from businesses and back into the hands of computer owners, where it belongs.

I believe they're talking about Windows 11's requirements, for processors in particular. Some relatively recent systems like those built around the first Ryzens weren't supported, thus putting them in the "devices that don't run Windows" category.