But you have a really hard time figuring out if you break some patents while developing software. Even lawyers and courts often have a hard time figuring out if something steps on a patent or not. As software developer where you develop new things every day you can basically only close your eyes and code on hoping you don't trigger too many patent mines. Patents belong as little in writing software as they belong in writing other things like books, articles or speeches.
Take it another way. Write software in the US, and as soon as you're making money, you run the risk of being sued by a patent troll in Eastern Texas. Write software in France, you run no such risk (some would even maliciously say that you don't run the risk of making money).