Yeah - I kind of agree with what both Corpsey and Luka are saying, though I wouldn't want to claim that Shackleton is 'shit'. It's not so much that I don't like his work; most of what I've heard I can appreciate in some way, albeit some things more than others. It's more that I feel there are some aspects to both his overall project (as I much as I can understand it) and the way people receive it that are worthy of being critiqued, but seem to have avoided being so up till now - hence the sacred cow status.
My main problem with his music is that, to my ears, it employs all the classic signifiers of being 'deep' and 'serious' - long tracks, lack of obvious hooks, use of sampled analogue sounds and generally warm textures, use of samples in seemingly 'meaningful' but unspecified ways -, but without actually delivering anything that is genuinely challenging, or indeed just anything that is really new. His tunes aren't all
that dark, neither are they
really all that transcendent; the beats and textures are never
very weird and twisted, too often the tunes just seem to drift along in a rather solemn fashion.
I also really feel that the stance of 'he doesn't use loops to build his percussion tracks!!!' (Oh gee oh wow!) that I've heard mentioned by fans of his on several occassions is very much the rhythmic equivalent of the fallacy Slothrop pointed out in relation to post-Basic Channel artists insisting you need to spend silly ammounts of money on amassing vintage analogue sound equipment in order to make your music 'really warm and human'. Or indeed the insistence that it's never ok to use preset sounds on synths or software. Some of the most rhythmically exciting and involving music I've ever heard, from ardcore, jungle, hip-hop, funky and many other areas, uses drum/percussion loops of some form or another, I don't see why it should be viewed as an inferior method.
Another thing that's often argued in his favour is that he's one of the few dubstep producers to use 'ethnic'/'tribal' samples in a 'responsible' way, providing some insight on the culture they come from rather than just using them to add a bit of exotic flavour. I'm not so sure though - maybe he isn't as bad as some, fair enough, but the samples still seem pretty non-specific to me, they seem to usually just signify 'meditative' and or 'mysterious', there's no real engagement with the role they play either in their own culture or in ours. Obv it's only one tune, but something like I Am Animal just seems naff - the title, the tune centering on heavy breathing plus repetetive hand percussion, then to top it off the corny cover drawing of skeletons playing the bongos, it all seems to add up to primitivism of cliched and patronising kind. (That's another minor gripe I have with him, some of his tune titles - I mean, I Want To Eat You, how old are you Shack, 12?

).
But I wouldn't want to overemphasise that whole aspcect, because as I've said the real drawback to me is that, to borrow mistersloane's terminology, the whole atmosphere of his work just feels a bit 'sixth form'. I know that might sound like a cheap shot but it's genuinely how I feel. It's odd too, because what he's doing is clearly quite close to a number of other artists - Peverelist in some ways, Loefah in others - that I not only really like but would defend the merit of at some length.
I dunno if that all explains it well. To finish on a positive note, I'll say that imo Naked, Hypno Angel and You Bring Me Down are all genuinely excellent tunes.