the reference to core *nix distributions is simply erroneous here. Multimedia systems are much more susceptible because they invariably interact, at some point, directly with hardware.
If you're talking about the many eyes make shallow bugs ideas, this is a fallacy. While I'm a big fan of open source, making the source open does not avoid bugs, where open source does come into its own once a bug has been identified.
Apple's developers have made a common mistake that probably could and should have been caught by code review, testing and static analysis. But Apple steadfastly continues to refuse to improve its release and update procedures, so that, instead of frequently releasing minor patches, it prefers to release monolithic sets updates and new features once a quarter, which often and unsursprisingly introduce new bugs because of their scope scale. But they can point to millions of satisfied customers – I've got a Mac myself but no I-Thingy and I prefer not to live on the bleeding edge, usually keeping at least one major version behind – no matter what we say.