This is a reasonable analysis. I guess because we are in a (silent) Cold War 2.0 and the world population became disillusioned with globalisation, billionaires building their own bunker is their insurance policy should the world is thrown into another chaos. After all, many countries who could afford did build bunkers for their citizens during the first Cold War, in case we decide launch nukes and extinct ourselves. Billionaires building their own bunkers is not different.

But on the one hand, there could be something intentionally sinister. Several billionaires, especially Peter Thiel and Elon Musk, are accelerationists. They see the world is going to end and so might as well speed it up and get on with. Although, they want to rule the ashes after. That's their idea.

It's his version of a mancave.

That's why the oligarchs are intent on accelerating the development of AI. They want robot guards that they could have more control over.

It's a bunker only if they are the ones who can open the door.

Making it uncoool is cool, but more importantly, unionize.

Make it uncool to work on their yachts, or in their homes, or as their driver, etc.

Hang on a sec, some of these jobs come with the opportunity to, uh, do something very cool.

...

Murder him? Nahh put the explosive collar on his neck with help of the IT guy and make him a bitch boy.

Cosplaying a "survivor"

It's also not necessarily indicative of anything. $100M is nothing for Zuckerberg, about 0.05% of his estimated net worth.

For context, excluding billionaires, your average 42 year old American (Zuckerberg's age) is worth about $135k*. 0.05% of $135k is about $68.

Given the choice, would you spend $68 to completely cover you just in case the world falls apart? Most people would. I certainly would.

*That still includes some pretty wealthy people that skew it higher, so don't feel bad if you're not even close in net worth. I'm sure not!

Because there is an impending global catastrophe they have ~~determined is unavoidable and unpreventable~~ caused through their greed and selfishness

There never were long term plans. Market economics is an evolutionary system. Business are the organisms with that system (so are nations, and any other organization made of people, really). So long as a business metabolizes human labor into profit, it continues. What looks like planning was really just ~two centuries of exponential growth. There is no driver's seat, not really. The capitalist that forsakes profit doesn't stay a capitalist long. The system itself imposes a greater selective pressure than any individual human will. It will outlast last its components... until it doesn't. Nothing can maintain both exponential growth and equilibrium within it's environment.

Mix bleach and ammonia and pipe the fumes in...

They're already working on that

With suicide collars on their butler's.

And, while they have the resources to do something to prevent it, they chose instead to make the situation worse.

They are not living in reality anymore. There is something within these Techbros that denies consensus reality and substitutes some kind of simulation of their own.

That's the reason this guy can build a bunker on an island close to the water on a volcano.

There is also some interesting symbolism in there.

They feel the need to hide from the people, because they know they would face the fate of Johan de Witt if the people ever found out what they did to them.