My guess is they're pitching themselves to investors as a logistics company with far larger aspiration than just replacing taxi's. They want to replace Fedex too. It's the only way to justify their valuation. A lot is possible once you have a network of locked-in, under-employed workers available at the push of a button. Point-to-point deliveries are a lot harder to pull off than the old hub and spoke model, but Uber have put a lot of the foundation in place to move into other types of point-to-point deliveries.