This theory is old. Not only Marc Faber, Warren Buffet and even JPMorgan Chase CEO Jamie Dimon called BTC a bubble and Fraud with no future. But after that again JPMorgan Chase CEO Jamie Dimon said he regrets calling Bitcoin a “fraud”. Moreover, Dimon said an interview with Fox Business “I just have a different opinion than other people”. So I now don't believe in all these non sense rumour now.
Since January 2018, Bitcoin fell to $5,900. Now it is $8,200