I would have to go with the latter. I think it is mostly an act (and sometimes a bout of stupidity).
Blaine is a perfect example. In interviews, he stays completely in character. And thats what it is, a character. When you realize he isn't simply doing stunts, but magic, his character comes to light. When he talks about how he wanted to do it to challenge death or to challenge fear, but you know he was doing more than meets the eye, it illegitimatizes his character.
Let me put it another way. If he REALLY wanted to cheat death, he would do straight stunts, not illusions guised as stunts.
But I do commend him for staying in character.
As for some simply being ignorant, let me retell a story I recently aquired from my friend and mentor Andy Dallas. Someone was doing an escape from within something on fire. Andy enquired as to what type of oxygen supply he was going to use. The fellow said, Huh?
Andy explained that he would need oxygen because the fire would use all the air. The other gentleman said, Oh. I didnt think of that.
The escape was scheduled for 2 from that day.
I am sure there are some magicians out there with a death wish of sorts, but there are also many accountants, clerks, and lawyers that have the same.
Just my thoughts. Cheers.