Ramzi Amri, of the Harvard Medical Faculty (department of surgical oncology) believes that the answer to this question is yes:
I have done 1.5 years of research on the type of tumor that affected Steve Jobs and have some strong opinions on his case, not only as an admirer of his work, but also as a cancer researcher who has the impression that his disease course has been far from optimal.
Let me cut to the chase: Mr. Jobs allegedly chose to undergo all sorts of alternative treatment options before opting for conventional medicine. This was, of course, a freedom he had all the rights to take, but given the circumstances it seems sound to assume that Mr. Jobs' choice for alternative medicine has eventually led to an unnecessary death.
He goes on to explain why in some detail - do take a look.
As David Brooks has pointed out, Jobs's worldview was formed at the intersection of very different cultures - Californian hippy spirituality, computer geekdom, and 1980s enterpreneurialism. Living that culture clash was part of what made him great. It also helps explain why somebody so brilliant and scientifically literate could put their faith in the unscientific, even at the risk of their own life.