No, he's not squandering anything. He's placing a higher value on time with his kids and wife than on time with an "ambitious" founder. No one deserves anything or is required to do anything.
From what primary facts does such a moral imperative arise? I would suggest that there is no such moral imperative at all and no one should accept that there is until the foundation of such an imperative is clearly and rationally stated. Many make the presumptive leap that morality must necessarily be altruistic with little rational basis for that leap. I disagree that genuine altruism is a moral necessity and will do so until I see substantial, rational arguments as to why altruist moral systems are superior to egoist moral systems. (note that benevolence != altruistic and exists comfortably within egoist moral systems).
"With great power comes great responsibility."
"To whom much is given, much is required."
That kind of thing.
It's amazing how few people in Silicon Valley make a billion dollars and then go on to do anything useful with it at all.
This criticism applies to the ten thousand people, like Sacca, that made a fortune off Silicon Valley and then "called in rich."
What would you think of Bill Gates had he not put his fortune to good use?