Ask HN: Survivor Bias. Why don't we focus more on startups that fail?

I think this comes from a book somewhere or other but it was paraphrased to me:

During WWII planes that made it back from combat missions were analyzed to be reinforced. They found that these planes were shot in the wings and tail so they reinforced those areas. Really though, planes shot in the fuselage were much less likely to make it back so they should have reinforced that area. They were biased by trying to avoid the problems the survivors faced.

So my question is: why don't we try to learn more from startups that fail instead of focusing so much on the successes?