This has nothing to do with microsoft making a mistake for once.
They're merely being efficient. They're putting in a security measure that is too new for most processors to handle. The only reason this feature only exists on AMD Athlon64's and the top end server processors is because these are the newest processors on the market. Its one of the big selling points of the AMD Athlon64 is that it includes so called 'hardware anti-virus'. Its not missing support for intel chips, its the chips themselves that are lacking.