While I agree for the most part that the M brand has been "watered down" in recent years. All the blame can't be placed on the marketing people. Nobody has commented on the fact that auto racing has changed. The Ferrari F40, Jaguar XJ220 & McLaren F1 were all cars that were homologated in order to race in an FIA series. Sadly FIA GT1 no longer exists. So car companies pour money into what racing series they deem gets them the most bang for the buck.
I'm not a huge Nascar fan, but that used to be THE "race on Sunday sell on Monday" series. No one can argue that the Chevy's and Fords that race there now have nothing in common with the street cars.
Yes M cars are still great cars. (note how i said cars) No they're not street versions of race cars anymore. But what really is?!? Unless you have gobs of money to spend...
Just my two cents.