Schiff believes in real equities. There is nothing backing blockchains except sentiment.
Bitcoin might have a limited number of coins. However, it is easy for people to replicate the code and create other coins; so Schiff is bearish.
Remember Schiff witnessed the popping of the dotcom bubble. The dotcom bubble was based on the belief that usership alone was sufficient to justify high market values. It crashed when people realized the dotbombs had no equity.
The dot com back back in 90's therefore we should buy a coin with real equalities and use case coin like hive and eth I guessed.