The btc/fiat fx rate volatility is present only during Bitcoin's exponential growth phase. When adoption plateaus (5 or 10 years??) then prices will be very stable, far more so than the current fiat system where they increase all the time, or unexpectedly because of commodites markets and international trade imbalances caused by unreliable fiat currencies..
It doesn't matter how many n00bs repeat that illogic, it still won't be correct.