You should probably add a disclaimer somewhere in OP. In no way does this represent actual people moving money for actual services, goods and whatever. It includes everything, including:
1) People moving money to their own (other) addresses/wallets.
2) Exchanges and other services moving their money.
3) Moving Bitcoin into cold-storage (can fall under both point 1 or 2).
When transactions were free, that was a good argument for why simple transaction volume is not representative. But now that transactions cost real money, it can be argued that the volume is representative, at least to some extent.
A good measure of the utility of a payment system is the amount of fees people are willing to pay to use it. Currently, people are paying $250,000 per day. I wonder how that compares to other payment systems.