The Chef took a risk that may have impacted his career negatively. That's not necessarily luck, that's an investment that payed off. And if you don't want the Chef to get rich, then don't offer him any stock - but then you do need to pay a higher salary.
It's funny that Zynga tries to paint this negative picture of Google's IPO, when clearly at Google everybody won tenfold, including founders and investors and being good employers is partly the reason for that. Zynga will never be Google and it starts with their attitude towards their employees.