Luck is a huge part of success. It's mythology that if you work hard enough for long enough that the world will become your oyster. Sweat and ingenuity are often necessary but not necessarily sufficient means to financial gain. No one launches from the same starting line nor runs along the same track. And don't forget that all the other smart folks out there are ravenously competing against you for those hotly desire…
The sad reality is, no matter how irrational is, people don't want to be around someone who is considered unlucky. Especially at a startup. I don't agree with this at all, but I'm saying it because I don't want to pretend that that psychological influence doesn't exist.