Just remember, the mandate for BMW M is to take an otherwise normal BMW and make it super. Like any good chef's they are limited by the quality of the ingredients.
The 3er, 5er and 6er are now big and heavy for to suit customer demands and for safety. M just makes them a lot better and faster. Blame BMW customers for making the cars bigger and heavier.
On the good side....
Name another company than can deliver 3 top-of-the-line variants at a rate of 1 / year. M5, M6, M3.... Audi's RS werks is a joke compared to M. AMG Black is a reaction to the fact their AMG's can't compete with the M's.
The Z10 is going to be a car built from the ground up by M.....I dare you to call it soft or lost when it comes out.
"Aerodynamics are for people who cannot build engines"......Enzo Ferrari