If you spend a lot of time on Reddit browsing /r/bitcoin or /r/cryptocurrency, you'll stumble upon a ton of hype. Not the good type of hype either. A lot of the content is "Bitcoin to a million dollars!!11one!!" or "Read this if you don't want to miss out on making money with [insert altcoin]!!!"
This is bad for the crypto community and gives cryptocurrencies a bad rep. Newbies buy-in and get burned quickly, then leave and vow to never come back. Reading the threads reminds me of the late 90's pump and dump schemes. I got burned once and know how it feels.
What makes crypto irrational is that an altcoin may have the best technology, but the only way for it to succeed is to get mass adoption. One way to do that is through hype. Even celebs are shilling crypto *eye roll*