BMW M didn't lost its way, it's the car industry that actually is loosing its way in the consumable products trend (amongst many other things), and BMW follows the fashion. Lots of new cars/liftings every year, lots of different spare parts to manage...
I have a E39 model and I'm amazed how easy I can find OEM parts over the internet for this model, and I'm sure BMW has still a lot of spares for this generation. I doubt it will be the same for all these new and very sophisticated models...What about running them in 10 years ?
Regarding the design or the drive qualities, yes they're very good, hopefully...but will they manage to stay in memories like the E28 M5, the E30 M3 or the E39 M5 ..., I'm not convinced. Rise of power, agressive look and gadgets in the extreme way we can see now may not be the recipe for iconic cars, but future will tell us. I'm maybe already too old to understand :p
1999 E39 M5 70k miles Japan Euro Spec LHD Import