Earlier quoted context omitted.
Well, they need to deliver them. Right now, 170K car is also 3 years of production for Tesla. Also it means if you want you Tesla Model 3 you have to wait until 2021 (time for Tesla to deliver the 115K one already booked) which is a long time to wait, 1 full leasing cycle. Of course, we basically have no details currently. The spec of the car, and the delivery capacity of Tesla will change until the actual release da…
Tesla is claiming they'll be able to produce 500,000 cars a year by the end of 2017 when the cars are finally available. This is a very agressive goal, and I'm not sure they can meet it, but I'm fairly certain their production capacity will be higher than it is today, especially given the unused capacity in the gigafactory that will come online over the next 1.5 years.
You can do alright as a brand with limited availability of luxury car like the Model S, but in the premium category you really need to be able to produce some number.
In Europe in particular, the big customer of that car segment is corporate leasing, unfortunately they need somewhat short lead time. For example, most of my friends in continental Europe have company car, but they only have 2 to 3 months to order and pick their car ( they also have a limited set of brands and models, but I'm sure Tesla will make the shortlist ), so that means until they can get a Tesla that fast, they will stay stuck with BMW/Mercedes for another 4 years cycle.