I don't consider them to be delusional. The only limit to Bitcoin's value is that it can't ever be worth more than all the fiat in circulation. Realistically, there won't ever be a time where that happens, but that's basically the only limit. On top of that, what if Bitcoin was worth $1 right now and someone tells you that in the future Bitcoin will be worth close to $20,000, and more precisely, within 10 years? I'm sure you would consider that person delusional as well. It's impossible to discard certain scenarios when it comes to Bitcoin as tiny dot in the financial world. A thing called Bitcoin has grown from nothing to something -- why can't it grow from something to a developed asset?