> Their track record is amazing, but ~97% of the business's they have invested in have not "made it big", so to speak.

That's entirely beside the point. They are specifically looking for those rare, billion dollar companies.

See: http://paulgraham.com/swan.html

The fact that most of the companies don't hit $1 billion is not at all relevant. That's to be expected when hunting for companies that are rare by definition (black swans). It speaks nothing to the intent of the investors.