Usually, facts get ignored amidst the roadshows, ads, and marketing that takes place before an IPO. There are a lot of vested interests in making sure that the IPO gets fully subscribed and that it has a positive opening on listing day. Very few investors actually have the bandwidth to look past the hype show. Those who do usually prefer to wait it out.
Having said that, not all IPOs are hyped. There will be those that offer value on the table right away. But I assume that they're in the minority.