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…
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.