That's because the bean counters have taken over. For instance, the wingtip wearers decided to use a cheaper option on the E39 clutch rationalizing that hardly anyone would use the car hard enough to see the difference between the high cost option and a cheaper cooking version. As a result the E39 M5 got a reputation for eating clutches. I suppose the accountants would point out that BMW lost money on each E34 M5 they built. Just my tuppence.