Being ahead on everything doesn't help if the larger players can pick and choose improvements and learn from your mistakes and adapt.
It really doesn't help when the leadership of said car company is erratic and eroding the goodwill of the brand while people generally feel comfortable with more established carmakers. I feel pretty confident that major automakers are going to be around in 10 years. Buying a Tesla already feels like a bit of a gamble to me just because of its newness.
With an economy that's already slowing it could really hurt them when it's likely fewer people are buying cars and will be more cautious about it when they do. "Maybe I'll hold off another year and see how the new crop of cars compares with the Tesla."