This argument presumes the value of the transactions will justify exorbitant fees. That will end Bitcoin as a currency. I can see their point, but it's premature. Bitcoin isn't ready to replace gold as a store of value, but it's already losing power in confirming transactions. Bitcoin should work towards staying relevant as a currency until the market deems it's better as something else. While I agree with Justus that the market can help find the best equilibrium between fees and block sizes, I think it's best to allow network science to determine that ratio rather than market exploiters.