Re: "the CPU manufacturers have asked the major OS producers what they want"
They really didn't ditch security for performance at the wrong time. Performance has been acceptable for most end user purposes roughly since the Core2Quad came out. Spectre has affected everything since the pentium, that's fourteen years of 'everyone needs more speed'. You can argue over the necessity of embedded management engines as well, but modern chips have additional features that (in general) improve security.
Security does not sell product for anything other than a very specialist market. Witness the horrendous whinging that occurred upon the release of Vista and the UAC - it was very slightly over the top, but not particularly so, and Windows 7 and subsequent releases are less secure by default.
I don't see people putting their money where their mouth is and buying more secure systems, so it's the same as usual : commodity platforms with good enough security and occasional patches.
Biting the hand that feeds IT
