Comment Re:A terrible mistake. (Score 4, Interesting) 297
I suspect the main reason is even though you may have to get a stopwatch out to tell the difference on a desktop, CLR/.NET does not have native performance which will show when you try to run them on thin (as in mm) devices. Most significantly you probably need to fit twice as much RAM in the case, i would guess memory bandwidth and cache sizes also are not friendly to performance and it would cost users battery time as no one would use the low power APIs.
The other things i can think of is that they don't want rushed ports to Metro and maybe it was easier to start from scratch.