It happens outside the U.S. as well, but the U.S. has a particularly weak form of democracy which makes it more prone to regulatory capture. In particular, money is a more powerful policial level in the U.S. than in most other democracies, and that creates a positive feedback loop that tends to encourage and reinforce regulatory capture (you use RC to make money, which you then turn around and use to pursue more RC in order to make more money...)
