If it were guaranteed that the price of bitcoin would stay the same as it is today, would you still buy it? My guess is, the answer is no. But if its value lies in being a currency, price stability is essential. And if your answer is no, how is it then not just a Ponzi scheme? In other words, everyone is buying it on the hope of someone paying more for it in the future, not to use it as a currency.
Honestly, I do not care about the value of Bitcoin and I will still buy it. Yes, it is true that the value of Bitcoin is unstable but time will come that the value will become stable once it starts to mature. This is a new currency system, a new technology and we need to embrace it to become part of the future.