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)...