There are some problems that just aren't amenable to the startup approach. The Manhattan Project wasn't three guys in a garage living on ramen noodles for a year. Neither was the Apollo program. Some problems just require huge amounts of people, money and time to crack -- and even then, as you correctly note, there's no guarantee you'll actually be the one to crack them. (Ask the Germans who worked on their A-bomb project, or the Russians who worked on their moon shot.)

The problem is that, when you're a VC, the only model you have to apply to problems is the startup model. And when all you have is a hammer, etc.