If we assume that there are only people with huge fortunes on bitcoin, then yes, it's too bad if the price goes down. But, except from those guys, there are the ones who are waiting to buy more. We never heard anything from them
Aside from the answers given above, maybe because people are more happy with the results of their hold, than be happy investing to something with risk, its already understood that if the price goes down=opportunity. However, there are those who are already holding btc so its really easy to understand why there are those who don't see it as happy as when the price goes up.
And as a human, we are more inclined to be happy with the reward, not by the time we spent money to invest with risk. In my case, or I think in everyone's case, we buy bitcoin and we didn't really post something like we are happy about it and so on. We just know its an opportunity, take it or not. When the btc price goes up, we are more into celebratory state, because we waited for it.
Ps. And because btc price going up means btc as a whole getting better isn't it, we wish that it could beat its highest price so far