You're way off with DEC. They were one of the first companies innovating with the Internet, and their computers kept up with plenty of innovation. Their issue was their business model was making expensive computers, and they couldn't adapt their business fast enough to the low cost personal computer model.
But besides being wrong about DEC, you're missing my point. Just because you're large and in charge doesn't guarantee prosperity in the future. Lots of things can bring a big company tumbling down, so you making the argument that Tesla is invincible in the future because of their current demand is very wrong. That was my point. My point had nothing to do with why DEC or Blackberry came tumbling down.
Nobody wrote that Tesla was invincible, nor would any rational person make such an absolute statement. Confidence in Tesla is high for *very* good reasons which don't relate to your analogous examples of Blackberry and DEC. A lot of people reading this have probably never heard of DEC, and I'm including the 50+ set like myself.
The problem is that your analogies don't fit Tesla. Both DEC and Blackberry were outmoded because they couldn't compete in a fundamental paradigm shift which affected their products. As mentioned before, the Blackberry was put down by the iPhone, and DEC saw the rise of Windows 95 on affordable and modular PC hardware which ensured its doom, and it wasn't just DEC. SGI went under too. Same reasons. That overpriced hardware (and software) went the way of the dodo, and the software was adapted (and evolved) to run on regular desktop PCs running Windows and its many subsequent variants.
There's nothing to indicate that Tesla will not be able to compete, nor is there any reason to think a fundamental paradigm shift is coming of the sort that killed off Blackberry and DEC. Quite the contrary, Tesla has a huge lead, a killer app (Supercharger network), is in the hearts and minds of consumers without any advertising, and continues to move forward with battery tech and execution of novel and courageous ideas with the best engineers any company could hope to attract.
And, the CEO has a successful aerospace company on the side without being beholden to Big Oil or government handouts. How's that for gravitas?
This is not to say that Tesla is immune from a stock price collapse or 'going under', but there's little reason to believe such things given the available data.