Bradley, I totally understand where you're coming from and I also think that much of this kind of music is exactly as you say. But I would argue that there is a very small portion of it that is not. I love weird music, but not music that is weird for the sake of being weird. I find Braxton essentially unlistenable. But it's sort of like 12 tone music. While most of it is academic, distant and unlistenable, there is some of Schoenberg's work that is accessible, compelling and speaks directly to the human experience. Hindemith is another. I do think that you have somewhat missed my point because I think that Zorn's performance, despite it being his baby, is neither definitive nor dispositive. Experimental improvisation does not have to be inaccessible any more than any other kind of music, it's just that so many musicians chose to make it so. This applies equally to Cobra. I disagree with the idea that being a game makes the music secondary, but I do think that it must be taken into account.
I think the reaction to this is very similar to the reaction that my wife got a number of years back when she was invited by the Denver Art Museum to collaborate with a modern art show they had as a perfume designer. Because of her background in painting, she had an affinity for the artists represented (interestingly, some of them were part of my childhood on account of my parents being artists in that general community, so it brought together various parts of my life quite nicely) and in fact had some of them in mind when mulling over her work. So, she brought to fruition a series she'd been contemplating for quite some time, which was a line of fragrance based on her perception of colors. You can see it here:
http://www.dshperfumes.com/shop/product-category/collection/chroma-collection/. At the opening, she was stationed at the door to the gallery and invited the patrons to smell the exhibit. While some people got it, there were quite a few who were puzzled because to them, perfume was something you wear to smell good. They didn't understand the idea of fragrance as pure art form and that it's just as valid to smell interesting. That isn't to say that you can't wear it (just like you can consider experimental improvisation as functional music), but it does require looking at the concepts of art from a new perspective. Now, it is all in the nose of the beholder and I think that Dawn is exceptionally gifted, so that what smells interesting also smells good, even if you aren't versed in the field. To prove my point, what began as a syntheasthetic exploration has become a perennial favorite in her lineup, with plenty of customers who don't know Hoffman from Motherwell.
So, the fact that Cobra as performed by Zorn, et al, doesn't sound good could be a function of the listener, but it could also be a function of the people who are interpreting it. From my perspective, all music I play, from Cobra to cover tunes, should be able to be understood and enjoyed by anyone, regardless of their academic background. My wife, who is somewhat conversant in music but has zero tolerance for self-indulgence or other wankery (she can be devastating in her critiques of music that is inaccessible) loved Cobra as did the other non-musicians in the audience. It was not your hip New York audience, the population of which in Colorado could have fit in the bathroom, but a wide range of people interested in something different. There were no squealing brakes, chalkboards or small furry animals. There were plenty of men on the street. The audience was tuned into the ensemble because the ensemble was tuned into the audience.