A lot of the tech companies that aren't here anymore, or only exist as a division of some other company were innovators who failed to keep up with shifts in the underlying technology. Wang and Digital Equipment were big in the days of the minicomputer of the late 60s and early 70s. When the tech changed and desktop computers could do everything a minicomputer could do and more, their market began to dry up.
Microsoft is in the same decline those other tech giants once were in because their core competency was desktop computing and while there is still a market for that, it's shrunk as consumers have gone to handheld devices that run different software. Apple stayed relevant longer by being on the cutting edge of some of the changes over the last 15 years. However with Steve Jobs gone, it's still an open question whether Apple will continue to be the company pushing the envelope. They have a lot of cash so they will remain strong for a long time, but they may fall from the ranks of the cutting edge.
In Tesla's car business, they are the cutting edge. They are years ahead of anyone else and there are a lot of tech startup companies trying to catch up and more traditional car companies are dabbling with electric vehicles while trying to ignore the titanic shifts in the market Tesla could trigger with the Model 3.
Tesla could miscalculate with the Model 3 and get into trouble. I've heard one of the Google founders have a standing offer to bail them out if they get into trouble. If the Model 3 is the success it looks like it might be at this point, Tesla could end up absorbing one of today's major car companies to get access to ready built factories on many continents.
Tesla Energy is a bit of a different animal. The market is crowded with players who have similar tech. Tesla does have the advantage of being able to build large scale li-ion storage arrays. Something nobody else can compete with on the same scale. They also have the most prominent name in the alternative energy business and a reputation for making a quality product. Their equipment has the kind of reputation HP's did back before Carly Fiorina ruined the company.
HP made Cadillac equipment. Back in the 80s, if you wanted the best scientific calculator, it was HP. In the 90s if you wanted the best printer, it was HP. They also were the best brand for many pieces of industrial equipment too. I worked as a contractor for a maker of medical equipment in the Seattle area. One of their competitors was HP and the owner hated HP. One day I was over in an area where the drafting department was and noticed in the corner was an HP plotter. The industry standard in large format plotters. I went over and looked at it more closely and they had taped over all the HP logos, probably to please the president of the company who would be the type to have a cow about that sort of thing.
If Tesla can keep their reputation for quality in energy equipment, they can remain a leader even if they don't have tech that's way ahead of the rest of the pack like they do in the car industry.
Tesla being a Silicon Valley company is an advantage here. There are a lot of people working there who know how some of the great Valley companies became great and they know how the greats fell. Many witnessed both first hand. They know what mistakes not to make.
