whereas the first is the normYou mustn't have used linux in quite some time. It is not 'the norm' for things to have no linux drivers these days, unless you're using bleeding edge hardware. Yes, you'll run into more driver issues if you're using a philosophically-restricted version of linux like Debian, but for the most part, stuff just works these days.
especially for any multimedia etc work
Tell me, how well does OSX do with the latest nvidia and AMD graphics cards? Linux does a decent job of them, though the bleeding edge ones usually suck (especially on AMD, though there are proprietary drivers). If they're not latest-gen, then they definitely work fine. Linux supports a much wider variety of 'multimedia' gizmos than OSX does.
I mean, nvidia offers drivers for Solaris for download and yet not any for OSX.
Or were you just picking and choosing to make OSX sound better? If we're talking about stuff people like to use, then GPUs are far more popular than ADC cards (of which there's plenty of linux support anyway).