So, you do understand, at the basest level, where his isolation stems from- as billionaire specific as it may be.
I get it. I also don't think it's that easy to come up with a great second act, regardless of how much talent and brains you might exhibit with your first big hit idea. Look at how many people from the business and entertainment worlds fail to do it. The phrase "sophomore slump" was invented for a reason. I was just reading about the original youtube guys a few days ago. They've been trying feverishly for a hit second act, but all of their output since youtube has been pretty mediocre. I've never played Minecraft, but it seems to be mostly about a novel concept and those aren't easy to do.
Yes and no.
There is no indication that his isolation is due to his inability to come up with a "great second act." In fact, his isolation appears to be more relationally-based. From what has been said on this thread, hes never linked his isolation to his work productivity (coming up with something as lucrative as minecraft).
With that said, there are many ways to decrease isolation, which he has is not taking advantage of. He can easily volunteer his time to any organization that has a computer system--maybe help them overhaul their system, to make it easier for them to keep their records. It doesnt have to be groundbreaking, but its just an example of just ONE way for him to decrease his isolation, if his isolation is relationally-based.
Hes choosing to sit home and eat M and Ms.
Bill gates is worth 79 billion dollars and his time is invested in all different sorts of things.
Again, as VOD said, with who he is, he can work ANYWHERE. Shit, he doesnt even have to accept a paycheck. There are millions of ways to give back. Hes choosing to complain on instagram.