Is there a way to use GNU readline motion and editing key bindings in GUI frameworks like GTK+, Qt, etc.?

Over the years I have grown accustomed to readline's key bindings in the terminal (e.g.: ctrl+a: move to the line start, ctrl+e: move to the line end, etc.) and I find it annoying not to be able to use the same bindings in GUI input fields.

How come there isn't widespread support for this, and instead GUI frameworks use a different set of key bindings (e.g.: ctrl+a: select all)?