You know chevy really knows how to do it right in terms of offerings. They have stayed true to the corvette brand. Not only does it get better each year, but it gets faster and higher quality interior and more luxurious. It also gets lighter and more performance oriented. To boot they manage to get better gas mileage without ditching their classic high hp/torque v8 layout.
M could take a page out of the book of what corvette does. One damn division in BMW could have stayed true to its heritage and it would only be a better brand for it. The press it gets from being the absolute best performer in my view more than makes up for any lost sales due to any m car being "too sporty"
COmpromise is great in terms of a brands entire offering but if you kill your niche segments which brought you the majority of good press than you are shooting yourself in the foot