1. Tesla Motors makes money on regulatory credits that conventional automakers must purchase in order to offset their ICE vehicle production. That's actually Tesla's only source of profit. Unfortunately for Tesla Motors, those regulatory credits aren't going to be in such high demand in a world where major automakers each produce hundreds of thousands of electric vehicles.
2. Tesla Motors doesn't currently compete on things like build quality and fit/finish, because the major factor determining whether you want to buy a Tesla is whether you want to buy an electric car. However, the time will come when you can get a mainstream electric car with the interior of an Audi, or the reliability of a Toyota, or the utility of a Ford truck. That competitive environment would be a wind shift for Tesla's business, not to mention the amount of pressure that other automakers will put on Tesla's autonomous driving features in court and with regulators.