Venture capital firms aren't competing for "unicorns" simply out of vanity. They need to bet on firms with outsized returns because even in a cohort of pedigreed startups with plausible business plans and some degree of traction, most are going to fail.
Many of those failures are capable of generating reasonable incomes for employees and founders for years, but those incomes are not proxies for investment returns. That's another reason crowdfunding is dangerous: we have a skewed idea of "success", because to us, starting a company that lets us control our own destiny, build our resume, and earn a competitive salary for 10 years is a huge success. To a crowdfunding investor, the returns to investors are the only thing that matters.