Description of problem: The fail whale is irritating, unhelpful, and transfoms any gnome hiccup in total failure. Please make it possible to disable it (and auto-launch a term) so users who are not totally clueless get a chance to make some use of their computer when gnome3 fails Version-Release number of selected component (if applicable): gnome-tweak-tool-3.9.91-1.fc21.noarch
Unfortunately, there's no GSettings key to modify the behaviour of GNOME Shell in case of failure, unless I missed it. GNOME Tweak Tool provides customizations parameters only through Gsettings. I suggest you to ask such a feature upstream, by addressing a bug report to the GNOME Shell project instead.