An example that has nothing to do with Tesla: in 2015 I bought my very first brand new car -- a Toyota Prius C.

Being a software guy, I was immediately struck by Toyota's insistence on creating their own navigation and other software in a suite of applications that were vastly inferior to the best-of-breed applications like Google Maps, etc.

Rather than focusing on enabling the Prius display screen, etc to show the results of my phone-based navigation software, they built their own, which was awful.

Now, it's not that they couldn't do it. In other areas like media (music) and telecom (phone), the integration with the Prius system was tight, useful, and even fun.

The lesson (to me) was to "stick to your knitting", in this case making some of the best cars in the world. The chances that Toyota was also going to create navigation software that rivaled or surpassed Google was roughly zero.

That was a bad decision. Why it was made (to Sr. Dans' point)? Who knows.