Out of all the things I don't think stability was it.
I do think however that it was one of the following.. (And these are just my guesses)
AT&T - They want customers to pay for their bandwidth but not actually use it
Sirius XM - Perhaps they don't want NICEMAC to release this as they are working on their own official player. I can't see Sirius XM not wanting people to have something like this especially considering that the online listening is going to be an extra charge soon meaning more money for Sirius XM.
I am also wondering if on March 11th the way serving is done from Sirius XM is going to change which would cause StarPlyr not to work and thats why they cat approve it "at this time."
I can't see Apple holding this back and see no reason for them to do so. There are so many other stream music programs out there, Slacker, Pandora, IHEART RADIO and many others, this is just another streaming program for Apple.
I am wondering if NICEMAC has been working on this with Sirius XM or have said screw it, lets just do this. That relationship there (or lack of one) could explain a lot as well.