Hi,
I don't know music intimately like you folks do, but one of the bands that was best at changing times and still continuing, in my book, was Amon Duul 2. Another band that was very tough on time changes and combinations was Nektar in their best period.
I don't see it as a big deal, I just see it as the fact that rock/pop musicians are not advanced enough to play around with other things that have been a part of music history since the beginning of the 20th century. Even Terry Riley, had several things going at the same time, many of them using different time elements, albeit I thought they were mathematically matched to make it easier on the ear. Guru Guru in the early days with Ax Gernrich was also a terrific off the cuff time and such, and Mani Neumeier used to say that he never plays with the bass guitar ... he only plays with and against the guitarist ... and you could see that again when he toured with that Japanese thrash band!
I just think that (at times) we're too concerned with intellectualizing something that is not particularly worth discussing within a true/meaningful musical context ... but I will accept that I do not know music as far as you guys do from a playing standpoint!