Here in Chicago, Tortoise falls into the too hip to like category
Tortoise, being in definition a Chicago-based band has fallen into that phase here of being too popular to be liked by the scenesters (see Smashing Pumpkins). Every little sneeze they do is covered by the local major papers and zines, so the people in the know has disowned them in a public sense (though they still might listen to them, but would never tell friends). What has happened is the battle, like with most bands, is that once they reach the mainstream and move from under to overground, of being hip or not-hip. Here in Chicago, we like our bands to starve because in that way, we can say we discovered them first. Hey, once they make it, its time to move onto the next unknown, and etc., ad nauseum.
TNT was a great album because it mixed in different world sources within a jazz context. Standards was pretty not so good. I see Tortoise as being more of an extension of modern jazz than rock (or post-rock) or even Can-style Krautrock due to the looseness and improvisational nature of the players. Their early stuff (Millions of people) bring in such elements as gamelan textures, Afro-beat and even Brazilian influences. Medeski and crew also seem to drawing from this same pool but more from the period of soul jazz such as Jimmy Smith. In addition, some of the stuff Matthew Shipp with his Thirsty Ear series (especially the one with Spring Heel Jack) are exploring this territory. I see Tortoise as part of the vanguard of re-defining the world of jazz than rock, as each of these groups (which some members of Tortoise participate) take their unique sound and apply it to this format.