Today one can buy electric and/or hybrid cars from Ford, GM, Toyota, Honda, Nissan, BMW, Mercedes, VW, Volvo, Audi, and even Jaguar. They are not going to stop making gas guzzlers, but they are steadily increasing their commitment to electric cars.
If electric cars take over the mass market, most of them will be made by established carmakers who know how to crank out millions of cars per year and have thousands of dealerships across the country. I'm sure they will be grateful to Tesla for proving the concept, but the traditional automakers won't have much trouble ramping up production once they know the market is there.
By the way, I would love to have an electric car but I don't have anywhere to charge it because I live in an apartment without a garage. Charging it at work is not realistic for me -- we have some charging spots, but it's really difficult to get one because so many of my coworkers also want to use them. There are millions of customers like me who need the charging infrastructure to improve before electric car ownership becomes practical, and we are going to keep giving our money to the traditional automakers.