(1) People may get hurt. I was in an Uber two weeks ago where my driver talked about taking out a second line on his home to buy Bitcoin. By today's mark, he's lost money. That people who clearly have no idea what they're doing are being preyed on is disturbing to many, myself included.
(2) ICOs are a cesspool of frauds. They allow promoters to make money without putting anything up. That's different from early Bitcoin adopters, who actually put time or money or computing power at risk.
(3) Bitcoin is an article of faith. Discussions around its value often devolve into "does god exist" arguments.