I'm worried because family and friends of mine who are not tech oriented at all, are buying bitcoin as investments. They are my canary in the coal mine.
4 years ago, when btc hit $1000, it was my uncle who asked me to buy a couple. A few months later it dropped to $300.
Crypto currencies feel a lot more mainstream this time around. It makes me worried that a crash could actually impact the "real" (as in non-crypto) economy.