Supposedly, Tesla's cars themselves sell for more than their production cost. The loss comes in supporting Tesla-as-a-fuel-reseller* - aka the Supercharger network.

It would be like if Toyota started opening gas stations, and Camrys and RAV4s and Siennas and Tundras got almost-free gasoline. While these businesses are complementary, they're very different operations, and should at least be in separate business units, if not a subsidiary or partnership with an existing fuel supplier.

*Electricity of a specific voltage and amperage is now a motor vehicle fuel.