I agree it is disappointing, especially when you have purchased the PC within the last 4 years
however, the I7-5930K was launched around August 2014 and has since been discontinued, intel's support for it ends next week (13th July 2021), Customer Support Options for Discontinued Intel® Processors
when Microsoft's support for windows 10 ends in 2025 that CPU will be 11 years old and the device itself 7-8 years old. Windows 10 will continue to run after support ends.
Microsoft must move forward to make the most of new technology available, as new features will be added to windows 11 during its lifetime (like windows 10).
Excluding discontinued hardware from the minimum specs, is (perhaps) reasonable as the new features going forward will not be tested on them (or already known, internally, not to work)
or at least it is better to know now than find in two years they release an update that will not work on discontinued CPUs