Except that Microsoft sold windows 7 and 8 with 10 years of security update. That's part of the lisence, and now that are refusing to honor that promise.
Windows 8.1 still has 6 years of security updates left. Anybody who bought windows 8.1 four years ago and wants a new processor has to give up over half of the support they bought.
This move is purely a greed filled money grab to force users to buy windows 10. I'm sure it's going to backfire PR wise, and may slow down the purchase of new hardware on top of said hardware offering only negligible benefit from five year old platforms.
Not supporting new features on old software is one thing. MS refusing to patch windows 7 and windows 8 to benefit from AMD's new features makes sense, as both are out of the feature update windows. But to refuse SECURITY PATCHES on older software running on newer hardware? There is no technical reason to do that. That move is going to piss off end users, and business users who are still running windows 7, and are basically being told they are not allowed to buy any new hardware for the next three years to run the OS they bought from MS, until they fork overs loads of cash to MS for the newest version, even though their is no technical reason the new hardware cant run 7. Especially places like hospitals, banks, and schools that have to support old software that vendors wont update until the last minute are all going to pitch a fit over this move.