
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