Stanford Welfare and chicken-hawking.
Stanford Welfare sometimes works out. Snapchat wouldn't exist without Stanford Welfare but it's now valued at billions. It may not be good for the world but it would have been a good investment-- assuming it can find liquidity before a Flight to Substance (which is quite possible, because anyone who claims to know when an F2S will happen is wrong; no one knows).
Chicken-hawking is when a middle-aged man takes a young sociopath as protege in order to resolve a midlife crisis and live vicariously through him. People like Duplan appeal to such people. When your goal is to live vicariously through someone, you want to fund someone who'll go a bit wild with that money, not someone who'll be committed to the "boring" task of building a business.