Emin Gun Sirer, a professor at Cornell University and a blockchain expert, recently questioned the technical value of Bitcoin. Sirer believes that it is an indisputable fact that the BTC network is relatively slow and inefficient, but the BTC extremists' response to this evaluation is really flattering. In response to an article about Bitcoin ATM machine fraud, Sirer pointed out that the thief is only using the basic flaws of the Bitcoin network – the slow trading time, the ability to steal the user's bitcoin. The number of global cryptocurrency ATM machines is continuing to grow, and some people have taken a more risky approach to improving the user experience, causing many customers to lose money, but this business model of ATM machines is still running. Sirer reiterated that the BTC network has been around for more than a decade and its design is no longer suitable for most use cases, forcing the company to take on the risk of causing customers to lose money. He believes that the BTC extremist community is similar to a cult and they cannot accept the reality of BTC operations.