How is the statement “cryptocurrencies are bullshit scams” different from me saying “the world wide web is a bullshit scam” in its actual substance? Regards, “Crypto-bro”

The professor isn't thinking 4th dimensionally. All time travelers until the end of time that have affected the past have already done so and we live in the after effects. There is no way of knowing that these events aren't muted versions of our "original" history. Maybe Hitler won World War 2?