Thanks for taking time to write this article. I think far too little people remember downturns and don't realize that there are multiple instances when pre-IPO valuations are actually higher than post-IPO. Down rounds aren't uncommon. Also, it's fairly common to see stock prices go down immediately after IPO for the first few months.
FaceBook being a classic example. More than halved in value in the first 3 months, now 8.5 X IPO price after 8 years.