What I'm more interested in is what *you* think is missing most or just plain wrong about the situation.
I started using linux for audio primarily for sooperlooper, which at the time (over ten years ago i think) was the best if not the only EDP emulation for any platform. It worked great then, and it still works great, so from that perspective, nothing is wrong with linux audio for me, except for the constant hand-wringing and complaining that something is wrong with linux audio!
But of course, that is not the whole picture. Every now and then I wish there was a native linux audiomulch equivalent, for example, but then I usually get to thinking how wrong-headed such desires seem. Windows or OSX never really evolved as audio platforms trying to emulate Windows or OSX so much, they evolved as platforms for music creation in their own terms. That's somewhat naive and an over simplification I realize, because for sure different software packages emulated and influenced each other, and even MS and Apple have always had their tensions about who truly innovated various features (and even linux can stake a claim in that respect).
But my point is that expecting linux to be just like one of those platforms seems dunderheaded to me. So one of the things wrong with linux audio (for me) is the constant stream of expectations to replicate the experience of other platforms. It may happen, but I don't think it is a worthy drive for development. Yes, certain features may be worth emulating, but often times I get the feeling that people have a working setup on another platform, and then complain mostly because they have to give that up when they switch platforms. They then get increasingly frustrated as they realize things will just not be the same as they were when they had a working setup on the other platform. Which often makes me question why some people switch at all.
A lot of the points raised in this thread are perfectly valid I'm sure from the perspective of the individuals raising them, and that's what this thread is about, but I'm going to take a stand against what seems to a trend of slagging the "audio geeks". For me that is exactly what makes linux unique, interesting, fun, and yes, sometimes frustrating. It is a system where the whole system is available to play and learn and grow as you grow as a musician or sound designer. Its never-ending openness and diversity limits its effectiveness in emulating windows or OSX, but linux offers an open palette of learning opportunities. Linux has taught me more about system design and the bigger picture of digital audio than Windows and OSX ever did. Of course, that's hard to quantify because who knows what might have happened if I didn't switch all those years ago (for one thing I might have made more music and spent less time learning about systems), but linux is what it is and I'd rather spend time taking advantage of what it is and then bemoaning what it isn't, as difficult as that can be sometimes.