I think a lot of HN users like to think of themselves as early adopters of new technology and are disappointed for missing out on the crypto highs at the end of 2017. I think they feel if they could have been in the loop at that time they could have cashed out. Thus crypto discussions are going to have a lot of negativity in the comments since the best way to make yourself feel better about it is to pretend it was a scam all along and you really didn't miss out. My 2 cents of course :)