I don't think there's necessarily any "human failing" involved here. At one point, Google was doing things that were inspiring and significantly changed how people use computers. Now, they're a lot more active in collecting personal data and I can't name one product they've released in the last five years that I'm excited about. My opinion of Google has changed to reflect the current situation.
A similar thing happened with Microsoft. In the 90's, they basically paved the way for commodity hardware. I could buy an OS from them and run it on any hardware I liked. That was a big deal. Unfortunately, the software ecosystem stagnated because it was dominated by one company for so long. (I switched to Linux at the time and have been using it ever since, but Linux was successful in part because hardware was commodized.)
Tesla and Musk's other projects might follow a similar trajectory of doing amazing stuff for five or ten years and then coasting on their established reputation from then on. However, that's no reason not to be excited about the stuff they're doing now.
A similar thing happened with Microsoft. In the 90's, they basically paved the way for commodity hardware. I could buy an OS from them and run it on any hardware I liked. That was a big deal. Unfortunately, the software ecosystem stagnated because it was dominated by one company for so long. (I switched to Linux at the time and have been using it ever since, but Linux was successful in part because hardware was commodized.)
Tesla and Musk's other projects might follow a similar trajectory of doing amazing stuff for five or ten years and then coasting on their established reputation from then on. However, that's no reason not to be excited about the stuff they're doing now.