We're talking about people making a decision to go public or not. Those legal risks were there anyways (it's illegal to defraud shareholders, even by accident), and if you're raising an IPO you're gonna be skyrocketing your accounting and other overhead costs anyways.

Your single-minded obsession with SOX is missing about a million other general and business-specific factors that would go into this decision, many of which represent a much higher dollar figure than sarbox compliance.

Heck, the costs of actually executing the IPO probably dwarf typical sarbox compliance costs (this statistic totally made up but plausible).