I really approve that reason and would be my basis on why Bitcoin's value is fluctuating but what is hard to determine is why people needs it on some months because the fluctuation is totally random. People only panic sell when they needed the money in a rush but not their choice to sell it lower.
I bet that word unstable doesn't fit in the world of cryptocurrency well first reason of this is because cryptocurrency was decentralised currency meaning to say it is not adopted legally by the government and mostly not controlled by the government or any legality government. Second, bitcoin was a kind of cryptocurrency that's why my explanation regarding cryptocurrency was fit in bitcoin also. I think you should be used about being unstable of bitcoin.