[bamfly]

People and companies in the US have contributed a whole lot of hours to emulator development, such that it's plausible emulation would not be nearly as good as it is if such development were illegal in the US. Moreover, less effort may have been put into emulator development or emulation-based-product development by foreign companies, if they were legally unable to sell their products in the US, which is a large and rich market. Further, US copyright policy has a tendency to influence international copyright regimes, over the longer term.