To be fair, the founder didn't want to do IPO and according to rumors that was the reason why he was kicked out. All the toxic workplace stuff was just a narrative tool to make it happen more easily.

Also, it's a public market. No one is "holding the bag". This may be true if Uber crashed before the IPO because private investors can't easily sell, but once on the public and liquid market, it is the public investor's own choice to invest or divest in these companies.