100% true. Poorly configured anything puts you into a terrible situation. If you setup a firewall and do a DENY ALL or ALLOW ALL blindly, you're going to have a

100% true. Poorly configured anything puts you into a terrible situation. If you setup a firewall and do a DENY ALL or ALLOW ALL blindly, you're going to have a bad time. But IN GENERAL, properly configured SSO (heck, the defaults for most of the SSO providers) makes for a better user experience while increasing security.