What should the percentage have been?

The point I'm making is that my opinion is that the founders here were unfair and that American laborers should expect fairness, not that they paid them some specific amount less than they should have- though I suspect you know this. If you'd like to have a genuine discussion with me then feel free, but whatever you currently appear to be after I have no more interest in pursuing.

GitHub employees agreed to work for pay, both in competitive guaranteed wages (salary, health insurance and other benefits) and also with stock, which is not guaranteed. Sounds fair to me.

You don't think it's fair -- fine, but what would be fair?