It seems that the volume of BTC transactions being made for speculation still far outweighs the economic usage of BTC. As long as that's true, volatility will still happen and we will still crash and tumble and spike back up over and over again.
In order for BTC to become a legitimate currency, its non-speculative economy will have to step up and become much bigger than it is now, so that the speculation and volatility becomes less of an issue. There's still a long way to go for that to happen.
Every person that makes your argument misses out on STORE OF VALUE. Who cares about commerce? If me and enough liberbros agree that Bitcoin is better than any savings account we've ever had (which it is) then it can exist at any level just fine.