Having such beliefs with absolute certainty is incorrect, we don't have sufficient understanding for that, but weak beliefs multiplied by astronomical value lead to the same drastic actions, whose cost-benefit analysis doesn't take notice of small inconveniences such as being perceived to be crazy.

The unabomber performed some "drastic actions". I expect he didn't mind if he was "perceived to be crazy" by others - although he didn't want to plead insanity.