- Price fluctuations attract speculators, part of their fiat money actually finances Bitcoin development
- Bubbles attract media attention and newcomers
- Bubble bursts redistribute bitcoins from early adopters who fix their profits to newcomers who have a chance to buy cheap
- Temporary decline periods make people spend bitcoins or invest them in something other than mining, e. g. creating new services
Bitcoin's current price is just an arbitrary number, it may cost 0.0001$ or $10000. There are so many bright and talented people and organizations behind Bitcoin, in my opinion it is already too big to just disappear. It is more and more difficult to obtain bitcoins. Those who sell now hope to buy in later, but nobody can guarantee they succeed. Everybody should hoard at least 1 btc for their long term future (though it is not possible for everybody to have 1 btc, sorry).
