Because prices are human psychology. A lot of the movement in price is because of trading. I believe, that only a part of people who hold bitcoin, are "true" Bitcoiners. But those are getting more by the day. We are still early.

As an advanced Bitcoiner you won't think in fiat price anymore, only in sats.

One day this whole appendix (the fiat system) will fall away, including trading and 'price'.