I'm likely to be on the wrong side of this argument, but part of my gets upset every time I hear about a founder leaving their fast-growing company. Great companies are built by the kinds of founders who don't just want to start something, they want to build and scale it into something world-changing.
Imagine Mark Zuckerberg leaving FB to "start something new". Imagine Bill Gates leaving MSFT early on to "experiment with some new ideas". Larry Ellison, Page and Brin, Jobs, etc all evolved with their companies. Why does it seem like this class of entrepreneurs is uninterested in seeing their companies out?
It's clear that there have been a lot of power struggles at Twitter. It's not clear how much of this departure is voluntary (i.e., the departure itself may be voluntary, but the conditions leading to it might have been a loss of control).
Finally, great companies have been built without their founders. Cisco and Intel lost/forced out their founders relatively early.
It didn't call back Jobs to get Jobs. It bought NeXT to be the foundation for their next OS. They chose NeXT over BeOS, and Jobs was NeXT's founder. Jobs didn't become active in Apple until later.
I've noticed that few people can be both a "starter" and a "maintainer". And even fewer actually enjoy it. There's a reason why only the really big names stay on for so long.
The people who start the company usually get bored when it comes time to go into stabilization mode. The people who maintain the company once it has stabilized usually don't like the uncertainty that comes with building a new idea.
In short, I don't think there's any reason to lament the new way of doing things. It's better for the company and it's better for the founders.
Actually I think it's usually the case where a company is founded by 2 or 3 really passionate people. Typically, there's one who's passion stays with the company for the test of times. With Microsoft, it was Bill Gates with Paul Allen leaving. With Apple, it was Steve Jobs with Wozniak no longer there. With Twitter, it Dorsey staying (after having been pushed out) with Evan leaving.
Almost all (if not all) entrepreneurs thrive on the creation process, but not all thrive on the nurturing part once a company reaches a certain level. Sometimes, the creative process just isn't a big enough part of the process anymore when the day-to-day stuff starts to take over a bigger part of a founder's time. Better to leave openly than to stay and not really have your heart in it.
These types of people don't have the DNA to run big companies long-term. But it's always interesting to see where they go next.
The person who starts a company may not be the best person to lead it when it's worth billions. I admire people like Craig Newmark of Craigslist for stepping out of the way, and people like Mark Zuckerberg of Facebook for continuing to lead.
Different people, different strokes. What is wrong with that? I also wouldn't put Mark Zuckerberg in the "class" of entrepreneurs you mentioned. If anything, he is a counter example to your argument.
Could you expand on why Mark Zuckerberg is not in the same "class" as the others? I'm not sure what makes him so different in the example, other than Facebook is not yet so old as the other companies.
Because ~99% of internet companies seem to either fail or be acquired, it's the nature of the beast. Only a handful of companies (like you mentioned Oracle, Google, Apple, Amazon) live long enough for a founder to even stay there.
Maybe they leave because they don't have the skill sets or experience to do so? It's one thing to get something going and make it successful, it's totally something else to make it huge and successful.
Imagine Mark Zuckerberg leaving FB to "start something new". Imagine Bill Gates leaving MSFT early on to "experiment with some new ideas". Larry Ellison, Page and Brin, Jobs, etc all evolved with their companies. Why does it seem like this class of entrepreneurs is uninterested in seeing their companies out?