critique: Bitcoin is too volatile to be a useful currency or store-of-value.
rebuttal: It's true that bitcoin historically has very high trading volatility. This is not a surprise for an asset whose market cap has grown to hundreds of billions of dollars, from 0 a decade ago. Furthermore, bitcoin's volatility *is* decreasing as it matures.
At this intermediate stage, where bitcoin's market cap is significant but still one or more orders of magnitude below where one might expect a mature global store of value to be, thinking of bitcoin as an emerging store of value is helpful. Ultimately, it's possible that once bitcoin achieves more maturity and a higher market cap, it can become a directly useful unit of account and medium of exchange as well.