Spoke to a blues rock fanatic yesterday, and he told me the reason prog rock is not widely loved is the fact that it does not groove, and therefore has no soul. 
I tried to explain to him that complex rhythms has the ability to groove fantastically, it all depends where you place the accents.  He basically closed the argument by saying that most people like to groove, and few like prog, so let the evidence speak for itself.  We ended up chatting about the Allman Brothers, a band we both like, and agreed to disagree on the previous subject.  I dont know, does prog rock not groove?