Steve Jobs was a brilliant guy in business who made idiotic medical decisions. It's tempting to call people morons - but the reality is that one of our problems as a society is that we assume that someone who is whip smart in one field has transferable skills. Not necessarily! In fact, that's incredibly rare!
Fair nuff.
I think he believed his own press releases. Learning the basics about his form of pancreatic cancer takes about 15 minutes. In three nights of reading, a well educated person can hold an intelligent conversation with a specialist.
Ignoring established treatments and outcomes come from fear or arrogance.