While many might lament the M halo cars new softer demeanor, if you want a good performance BMW, forget about driving a 520d (even though its a great car) and bagging the bragging rights at the pub that yours is basically the same as the one on the M5 (because it just isn't)...
Rather look nearer to the bottom end of the range; M135i, 135i coupe, anything with a 35 on it.
BMW are just making drivers cars more accessible (why I
'em) and for that you gotta stop worrying about numbers, snobbery and get on with buying what you like because its great to drive, if that's REALLY all you want.
I know people who wouldn't buy a 1M just because its got the '1' on it, and they want at least 3 or higher. If that is the way you think (and I suspect a few here do), then its your own fault for being so upset, so the M5 (sedan) and M6 (grand tourer of note) is slower than some real high powered muscle cars, who cares?
need to get over yourselves...
(Reminds me of Honda in the 1990's. Drive any new honda today to get an idea how far any company can go astray in pursuit of a quick buck.)