Blockchain is bigger then bitcoin. Bitcoin can crash to zero but it won't effect blockchain.
"Like many critics of the cryptocurrency price surge, Gates did say the underlying blockchain technology had its merits.
Blockchain eliminates the need for a third-party intermediary, such as a bank, by quickly creating a secure, permanent record of a transaction between two parties. Bitcoin is the first application of blockchain technology, and companies are exploring ways to apply blockchain to supply chain management, trading and other areas."