It does seem to me that patents are really intended to protect a specific design rather than the concept. I.e. a specific tire tread pattern or construction method can be patent protected, but just because Goodyear has a patent on a tire, doesn't mean that Michellen is infringing that patent by making a tire of their own, even if it's very similar in look, feel, function, etc. In fact, any lawsuit that tried to claim such a thing would be laughed out of the clerk's office before it even got filed. Why then do patent applications go through for things like shopping carts? I expect it's because the patent clerks don't have any grasp of 'software stuff'