FWIW, my take on that is that hitting just the login page is so infrequent the resources wasted would be trivial compared to the complexity of non-intuitive behavior. Just my $0.05.
It seems worthwhile to note that the behavior you'd like will be the default in CAS 4.0:
https://issues.jasig.org/browse/CAS-1219 M -- You are currently subscribed to [email protected] as: [email protected] To unsubscribe, change settings or access archives, see http://www.ja-sig.org/wiki/display/JSG/cas-user
