It's true that a number of smaller businesses have turned private to avoid SOX compliance.
It's also true that a number of very large businesses announced that they were going to list overseas, specifically to avoid SOX compliance. When SOX came out and the EURO was booming along with Asia, there was some intensely heated competitions for companies to go public under the competing exchanges. While it has somewhat been argued that SOX was more of a scapegoat, due to other exchange incentives. It does place American exchange agencies at a disadvantage when competing for new listings, as we no longer dominate the market by being the gratuitous destination. Granted, it is starting to slightly turn in our favor again. There has been some talk though, about whether the higher integrity in the financial picture that SOX intends to convey, is worth being a bit more restrictive on whom lists on the exchanges. It's highly arguable though.
I mentioned earlier, there's also restrictions on traditionally accepted business practices. There are restraints on B2B sales, under certain conditions. Accounting restrictions as TVDOC mentioned. As well as operational inventory management adjustments. Where I work, we actually ended up scrapping millions of dollars in inventory, during the initial SOX compliance period. Granted, that was due to poor implementation techniques by certain departments rather than the legislation requirements.
The argument for SOX is that all of these requirements and restraints, reduce the potential of numbers playing, and provide a more accurate financial picture of the company. Which allows the public investors to make informed decisions and have some faith in the facts being posted.