The Model S is much too big a car for me. That means there are others as well who would not buy that large a car. It was the right step to take after the Roadster. Four years ago Tesla did not have the money to built the Model S. The Roadster provided that money by showing what Tesla could accomplish and opening the door to investment and loans. So they dook a step downscale. Less-expensive car, appealing to a wider customer base, but still expensive.
I bought the Roadster because I could afford it. But my ideal car would have been the Bluestar: Smaller than the S (Civic size would be ideal for me) with a 160-mile range and performance in the economy family car range. (I love the power of the Roadster, but I don't need it and would have preferred a less-expensive car, as long as it was electric.)
So Bluestar is definitely the way to go to expand the Tesla brand. I'm a little disappointed they're building the Model X before Bluestar, but I understand the reasoning. They're using a lot of the Model S development to fill another big niche at reduced deselopment cost. But to argue against Bluestar is to suggest that Tesla should always remain a small and marginal company that has minimal impact on transportation overall. One of the reasons I support Tesla so strongly is Elon's vision to make a significant impact on transportation by building a car that the middle class can afford.