5% of venture capitalists have generated roughly 90% of the industry's profits

That's because of the winner-take-all properties of the tech industry. There's no reason to think that those 5% were smarter or even better-informed than the other 95%. They just happened to be the ones who guessed right, and the ones who guess wrong walk away with noting.

We have a long string of successful tech veterans going on to make wildly stupid decisions. Even the ones who win more than once often seem to be benefitting from the fact that they are the only ones invited to participate. They're not one-in-a-billion; they're one in a few hundred.