What about companies like IBM? The company was originally foundered in 1911, but you could say their heyday wasn't until half a century later (or even more), after the original founder had left.
>Although the initiative, and as such much of the credit for the birth of the information revolution, must go to Tom Jr., considerable courage was also displayed by his then aging father who, despite his long commitment to internal funding, backed his son to the hilt; reportedly with the words "It is harder to keep a business great than it is to build it."
Not saying this happened at IBM, but sometimes correct people can be promoted into correct positions, in which case the company keeps going just fine.
However, at some point any company is probably bound to promote wrong people, who will end up promoting/hiring the wrong people under them, eventually completely changing the course of the business.
It seems like the death of a company is inevitable.
It also happens that the circumstances that allowed a company to dominate come to an end. It would require heroic measures to move to a new form of dominance. Why should lightning strike again in the same place?
It's good when we allow them to fail gracefully. I would hate to see what unscrupulous stuff a failing Google could do with all our info being held hostage.