Personally, I think that if I had a really good plan for $100m I could probably raise it because there is a highly competitive sellers market for things that you can put that much money into and create value from it. I just don't have that plan. :)
There are a zillion holes to throw money down, but something that can sustain its value and grow? Bezos' decision was probably the same as a regular investment "team, market, product" call: there's a real problem that a lot of people have, and here is a long list of people who want to solve it but nobody has a complete solution yet, and if I had to choose the top ones to get exposure to - to make a difference on this problem, these two guys are the best ones I can find to figure out what the solution is, so I'm in for $100m apiece. Same game as any angel or startup investor, he's just playing at the three-comma table.
I genuinely believe the path to that table starts by challenging ourselves to think bigger, which means doubling down when it's the hardest, and testing assumptions when it's easy. It's not sufficient, but it is the necessary condition.
Think of a problem that people with effectively infinite resources would invest in solving and start working on it. To them $100m is a rounding error, what they don't see are credible plans or track records for making the change they would invest in. Jones and Andres had it. The money isn't a prize, it's an investment and a bet. I wish them luck.