Why do American keyboards have that horizontal enter key?

As a Brit, with plenty of notionally British keyboards to choose from (with £ signs for the price and the '3' key), too often there is this wrong-shaped horizontal enter key. What is the thinking behind that?

As for the article, mystery key pressing games might be incredibly clever in the parallel universe of the Apple cult, and even quite fun, particularly if you press the wrong keys deliberately, but I prefer the Ubuntu way, where you just have the keyboard for your locale selected, with the option to change it, if you really want to.