You're looking at this after the fact though.
Imagine 2 scenarios for a corporate chef in San Francisco, who expects his next job to last 10 years:
1) He goes work at Safeway, and earns $60K.
2) He goes to work at Google, and earns $50K with a very high risk lottery ticket that has an NPV of $200K, or $20K/year. (Say 1 in 100 shot of getting $20 million, or use Black-Sholes on an option)
Who are we to begrudge him if #2 pays out? The company does it because it's better for them than getting more VC money to pay the extra $10K.
For the chef, it's a better deal than Vegas, Lotto, or the options market.