Of course, startups usually do not do formal audits until they bring on investors who will insist upon them, i.e., typically VCs. Thus, this is just one more reason for a startup to try to bypass such funding sources and pursue less restrictive sources if possible (why add yet another $100K to the annual burn rate when you want above all to preserve cash and use it wisely?).
Combine this (and other factors) with the crimp that Sarbox has put on companies going public, and you have an environment where the value of VC funding (which typically is key to launching a startup on the road to going public) has depreciated.
A founder might look at this and think that this has little or no impact on his bootstrap or angel-funded startup that he plans to sell to Big Company X. But the effect on valuations is real. As with any negotiation, if you have fewer levers to use in the negotiating process, you will be at a relative disadvantage. If your company has no alternative but to be acquired in order to achieve a liquidity event, the buyers on the other side (i.e., potential acquirers) will factor this into their pricing to your detriment.
These sorts of changes may have hurt VCs but they have hurt entrepreneurs as well in limiting or eliminating funding options that were readily available to such parties in the pre-Sarbox era, leaving all parties poorer in the process.
These are real costs (as are the ones that fall on public companies directly, as noted in this piece), while the benefits of Sarbox to date have been dubious at best. Of course, the accountants, lawyers, regulators, etc. who benefit from the regulatory complexity through increased business and/or power will beg to differ, but this doesn't mean they are right.
On a final note, the Supreme Court case noted in this piece does raise the prospect that Sarbox will be declared unconstitutional and, should that happen, there may indeed be some real prospects for reform. The justices seemed skeptical about the constitutional argument during oral argument, however, and this may therefore go nowhere as a potential solution to the problems raised.