I agree that Bitcoin is currently perceived more as an investment than as a means of payment. But this is a natural stage — over time, as regulation and trust grow, it may become more widely used in transactions. Everything depends on the infrastructure and the willingness of businesses to accept such payments.
Let's say that over time, everyone familiar with Bitcoin will accept it as a means of payment for many things, but when most people won't want to spend Bitcoin on anything less valuable, perhaps fiat transactions will continue because people are no longer afraid to exchange paper money for more, especially if that paper is thrown away by buying valuable assets like Bitcoin. Rest assured that as Bitcoin gains value and is accepted by all companies and individuals, everyone will continue to safeguard and store it so carefully that there will be no longer any thought of wasting it by exchanging it for something of lesser value.