In my opinion, the last hardcore ///M-car was the M3 CSL. Now the M cars are powerful, heavy, luxurious and rather comfortable, but not really purpose build for track duty, like some of them used to be. The 1M even had a turbo engine, with plenty of throttle lag. The M135 does not seem very different to me. They are very good cars, but the original M spirit is fading.
I have noticed that the F20 gets a LOT of critical comments on the looks from Americans on most car forums. This can probably explain why USA is not getting this car. It simply does not fit the American taste. If BMW wanted to sell this car in USA, I guess they would have styled it more like a Ford F150! :-)
Here in Norway I get plenty of positive comments on the looks of the F20, maybe except for my rather special choice of wheels for it.