Sadly, because I find Hirst's work, along with many conceptual artists, to be somewhat dull. A purely personal assessement (and not intended as an attack) but I included it because I want to defend the inclusiveness of 'art' regardless of preference. Too often I've heard people who don't like this work say "It's just not art" - when it plainly is.

You are right, art does not divide neatly into aesthetic and conceptual or into any of the other catagories that have been invented for it. But I do think that the divisions exist, however fuzzy, with regards to the emphasis. It is also worth noting the distinction between formal and contextual beauty - ideas can have an aesthetic quality as well. People tend to judge art with regard to what they think the emphasis and media should be and so we hear people dismiss Hirst as non-sense, traditional art as irrelevant, or photography as a knack.