There's no big secret why Bill Nguyen can raise money. Once you have sold one company for $850 mil, you aren't going to have trouble raising money in the future.
There is so much money sloshing around, and people are so scared to miss a deal that they're willing to take all the risk up front. It's crazy, and doesn't work like that in any other industry I can think off..
And many other industries work this way. Biotech and oil & gas come to mind. In fact, the tax laws around carried interest were enacted to encourage oil & gas exploration.
Throwing money blindly and seeing what sticks doesn't seem to be the YC modus operandi. It is interesting to see the number of YC alumni who join other YC startups, or do a second start-up, with similar teams and a new idea.
I would hope to measure up to the YC standard, and get myself and my ideas accepted, when the timing is right.
http://techcrunch.com/2011/05/24/y-combinators-paul-graham-w...
B) Using other people's money is always a lesser risk.
C) Raising big money = big PR ("social proof").
And of course the mafia always needs to be cut into any good deal and requires a "taste" and to dip their beak.