There's a big difference between a VC round and the open market. The markets are often not driven by anything even related to the companies whose valuations fluctuate wildly by billions of dollars in under a second. They don't open to you (to same degree) to hostile takeovers, pump-dump schemes and naked short attacks. They force companies to kowtow to the opinionated whims of unaccountable analysts and focus on short term profits over long term strategy.