What's your take on personal finance re: private company stock?

I've only ever worked for public companies and receive real stock that I can sell immediately upon vesting. On here, I read many stories of compensation that seems to be ~50% cash and ~50% stock, usually vested over 4 years, but with the (huge) kicker that you don't get the shares if the company doesn't go public within N years. Is this common? I, of middle class means, am not looking to bet 50% of my compensation on black. This isn't a criticism of private companies, but why in all that is good would I turn down working for a public company that offers total comp that is a hair lighter (say 80 to 90% TC of a private company) for real shares that I can sell immediately? I have very important financial milestones in the next 5 to 10 years. I want to have kids and a home. I can't wait on a company going public or depending on paper shares that end up worthless. Am I reasonable in my thinking, preferring public companies with compensation I know will be usable? Again, this is not be critical of others and their goals. I know private companies going public can be a real windfall.