Not supporting the selector for .on() and .off() is a pretty serious limitation; catching bubbled events on child DOM elements is a super-common jQuery pattern,

Not supporting the selector for .on() and .off() is a pretty serious limitation; catching bubbled events on child DOM elements is a super-common jQuery pattern, and makes event-handling over a DOM that's having stuff added to it much more pleasant to write. It's also pretty fundamental to some third-party libraries that run on top of jQuery, like Backbone (at least if you use its View event handling).