I think good technical death metal is written by musicians with longer attention-spans. They have the ability to justify a part of a song in the context of what happens before and after it - they always keep an eye on the bigger picture. There's obviously other factors involved in making good music but I think the attention spans of the musicians comes into play throughout the development of these other factors, not just during the writing process. Overall I would say it comes down to intelligence, attention span and original methods of thought which aren't massively influenced by the general consensus of what is thought to be original.