B) It's straightforward - those companies are very often bought by other companies (because they have intrinsic value). The buyer purchases all of the shares from the shareholders (usually in cash), which realizes the value of the company.
I've worked for BigCo and startups, and don't have a degree. It has never been an issue, anywhere I've worked, ever. I've asked. They don't care. The only time it would matter is if it was a legal requirement for professional engineering (anything involving safety).
Yes, BigCo wants to hire middle of the spectrum folks who live in the suburbs and do a decent job for a fair wage. But they also want to (and do) hire hackers.