I have to disagree (don't know what other folks might think, though)
Personally, I use the US dollar (and the Russian ruble, for that matter) as a means for increasing my total BTC holdings as well as bitcoins to increase my holdings which are in dollars and rubles. I don't give any preference to any of these in general, but more specifically, I value Bitcoin higher than the rest of the stack because of its higher volatility. In other words, I can increase my total stack (denominated in any currency) faster through it than through other currencies. But ultimately, any of these are only tools for attaining other ends which would be hard to attain without money if possible at all