well that's the trade-off, isn't it? unless my app is speed-heavy, i'm not gonna spend the extra man-hours needed (that jquery saves me) so that website runs negligibly faster.
good luck ranking in google and explaining your self to your md when your major publishing site takes 20 seconds to load I wont mention any names but I know of two cases of this.
From experience where there is jquery there is normally at least a dozen other js files cut n pasted at random along with a similar number of css files with no thought to efficiency - hell most sites I se they can't even optimised the godamm images using Photoshop properly.
"JQuery is bad because some people who use it do unrelated things wrong"? Should I stop driving because some other people who use cars happen to cheat on their taxes?