
The current behavior wasn't designed, but was introduced in commit 84efaac52b to work around technical limitations when we were still using external tools like gnome-screensaver or gnome-session-quit to handle the actions. Those limitations are long gone, so it makes sense to make the actions consistent with the corresponding keyboard shortcuts: Leave the overview when launching an application, and leave it alone otherwise. https://bugzilla.gnome.org/show_bug.cgi?id=691900