Your arguments about compatibility with old browsers is great, but sadly the jQuery team doesn't actually believe that the problem they are solving should include compatibility with those versions of IE: the latest versions of jQuery decided that IE9 is the oldest version they are going to support going forward, as they didn't want to deal with the overhead (both in code and in development effort) of being a library designed to solve the problem of cross-browser JavaScript development... in a world where jQuery is just aiming for "improved syntax for DOM manipulation, compatible only with relatively recent browsers" (something I will argue has always been the case, due to their rather early deprecation of Safari 1.x), those examples cannot be dismissed: jQuery is just being used to avoid the complexity and verbosity of native APIs.