The volatility you're talking about is when you price bitcoins in fiat money in which the supply is constantly expanding (fiat), we are forced to use centrally controlled fiat money because that is what our masters demand we pay our taxes in, if we had a system of free banking who would use a currency that was centrally controlled by government? Everybody would be using things like gold, silver and bitcoins because they provide many more advantages as currency one of them being a reliable store of value.
And so what? This (and what you wrote after the emboldened text) doesn't change a thing about the fact - it's Bitcoin's volatility, not of the fiat currency you exchange it for. I have already written in my post that volatility (and stability for that matter) of a currency is predetermined by the size of the economy, i.e. the overall volume of goods and services that you can buy or have rendered to you. The money supply being
constantly expanding doesn't affect the volatility of the currency (just in case that was your point)...
Of course expansion of the money supply affects the volatility of a currency, look at the exchange value of USD for oil or food it's constantly changing (or getting worse), money is just a means of exchange so increasing the amount in circulation reduces the exchange value for other goods and currencies. If you look at the price of oil in gold you can see it's barely changed, what can we infer from this? Expansion of the money supply increases the volatility of a currency.
Bitcoin is volatile however because it's hard to tell what the owners of bitcoin are thinking, how much faith do they have in the dollar? Are they simply just speculating? But I believe there is a core group of bitcoin owners who recognise the economic problems currently facing many governments and they have lost faith in the currency issued by these governments and the true value of bitcoin lies in how much faith people have left in the current system and whether any competitors can create a currency that functions better than bitcoin.