It's different because this time it's VC money, not people's savings.
When a company is listed, the stock price better reflect the actual market value of the company (otherwise a dot-com bubble happens). However, if rich VCs like to bet on startups, that's expected to be a high-risk investment.
A little of it is pension funds or sovereign wealth funds, but most of it is from high-net-worth individuals. Investors are required to be financially sophisticated; they know the risks they're taking.
If VCs lose all their money, it won't be anything new. Only a tiny fraction of VCs provide a return, after you take out the managers' fees. Large firms pump money into VCs almost charitably or as a PR thing -- they rarely expect much out of it, and their portfolios certainly aren't made or broken by their VC bets.
When a company is listed, the stock price better reflect the actual market value of the company (otherwise a dot-com bubble happens). However, if rich VCs like to bet on startups, that's expected to be a high-risk investment.