"Eric Raymond has stepped in to defend his open-source colleague"
I suspect that RMS would dispute the "open-source colleague" bit, since he hates the term open source and refuses to be associated with it in any way.
Personally, I agree with RMS that the walled garden that Apple has created is a really bad thing.
My primary problem here isn't with the proprietary/closed nature of the software, it's that fact that if I use an iPhone/iPad I can only obtain my software through Apple (who choose what is and is not allowed) and as a developer I can only sell through Apple and have to accept their terms. This is highly anti-competitive and i'm amazed that the anti-trust people haven't shut this down.
If I buy a car I can choose where to have it serviced and buy spare parts or accessories. Some actions may invalidate the warranty, but I can still choose to perform those actions if I want to because it is MY car. If your car refused to start because you had installed a new radio from a third party dealer, how would you feel? Would you accept this? I don't think anybody would and yet millions seem to accept this kind of behaviour from Apple without a single thought.