[Entlin]

John Siracusa wrote about this very aptly 5 years ago: Avoiding Copland 2010 http://arstechnica.com/staff/fatbits/2005/09/1372.ars

Then he revisited it 10 months in 2010: http://arstechnica.com/apple/news/2010/06/copland-2010-revis...

And then he talked about it 2 weeks ago in the Hypercritical Podcast: http://5by5.tv/hypercritical/14

Abstract: new language and new API go hand in hand. A memory managed combo trades execution speed for faster program creation. Was already needed 5 years ago. The recent garbage collection additions don't cut it. Microsoft started working on their successor (.net) 10 years ago and now it's starting to look good. Apple gained some leeway when the iPhone happened. With ever improving CPUs on mobile devices, Apple still risks losing ground down the line.

Great podcast episode, I highly recommend it.

[ryannielsen]

You could also argue that, given the current success of iOS and Mac, Cocoa isn't a significant hinderance to Apple's platform's success.

(Not to say I wouldn't mind some significant advancements in Apple's preferred runtime, but there's strong evidence that the current runtime is actually quite suitable. If, as you say, .NET is only now starting to look good after a decade's worth of work, perhaps that wasn't the wisest investment on MS's part. Siracusa's been beating this drum for years and, like many of his crusades, I struggle to see how Apple suffers from not following his advice.)