I think the price is all that matter. Peace
It is the only big reason why traders like to trade on bitcoin vs altcoin and bitcoin vs fiat. However it has a downside, if the price falls too much people may convert all bitcoin to fiat and stop using bitcoin. However the chance is very less.
It has upside too. If the price rises fast people may convert more fiat to Bitcoin.
However, it is just for speculation.

It is the contrary. They will sell faster than a speeding bullet. It is called panic selling. They cant control their emotion of excitement seeing there is profit already and want to take it. That is why bitcoin price dont stay up. I mean way up.