This is a very good question. I also want to know if there are examples other than major successes like Google and Facebook.

One issue is when you want to hire people and you want to feel confident that you are offering them a "real chance" for financial success, even if it is a slim chance. I mean if you know that it is very likely that even when "you" have a win (whatever your goal is) and your investors have a win, still your employees don't benefit significantly, that will be a sad story.