Some people actually have reasons for doing things, and some just "do it because it looks cool".
Take Burial; he has concepts and ideas that drive his music, he's put out what is arguably one of the best pieces of electronic music in the last 10 years, but now Skrillex is copying him. Skrillex has no reason for attempting to enter the post-dub/future-garage world, aside from copying burial and following the trends. "Leaving" will never be recognized by anyone, but Archangel (and all of Untrue), is well-reviewed, recognized, and will be remembered for a long time.
What makes certain art particularly good is the conceptual leap; someone who has an idea thats so novel and interesting that it challenges the way people are currently doing things. Obviously it also has to be well executed; its a combination of someone who is very good at their craft and also very creative. Burial is one of those people, skrillex is not.
(weird example maybe, but it was the first comparison that came to mind)