Why should they? Any Intel Haswell processor or earlier will have "noticeable" slowdown for all users according to both Intel and Microsoft, and two of the variants do not affect AMD processors, so you can either pay more money for a less secure processor that will be more expensive to upgrade in the future, or you can go with the more secure AMD processor with a less expensive upgrade path.
Wait for things to be fixed, patched etc. There's a good chance the Intel cpu will still be faster than the AMD even after the fix. And with a Intel cpu you'll still be able to boot into Windows after the fix. Unlike alot of AMD cpu's.