Influential economist and fierce Bitcoin (CRYPTO: BTC) critic Peter Schiff stated that his pessimism about the leading cryptocurrency may be proven wrong if it becomes a mainstream payment medium. What happened: During a debate with Jack Mallers, CEO of Bitcoin startup Strike, Schiff indicated that broader adoption of Bitcoin as a payment alternative to existing fiat currencies might change his opinion, starting from something as basic as paying for a dinner at a restaurant with the digital coin. “I can buy insurance policies, and they have Bitcoin benefits. I pay my premiums in Bitcoin. I get…