Apple cares, because they don't want any significant portion of their application marketplace on the iThings to be controlled by any single API vendor, which wo

Apple cares, because they don't want any significant portion of their application marketplace on the iThings to be controlled by any single API vendor, which would give that vendor market and PR leverage that Apple doesn't want them to have. It's not about compatability or looks or anything else... Just think about the transition from PPC to INtel. For Xcode users - this was pretty much cake. The had to add some code in some cases, but it was a fairly easy task. If, on the other hand, some other compiler run by someone else, hostile to apple, was the preferred platform for most apple developers, apple would have had a hell of a time pulling off a move like that.