Bruce may not use an autocue (what my Dad used to call an "idiotprompt") but his memory isn't perfect either: he has been known to forget the lyrics of Maiden songs or sing the wrong words. But when that happens he just wings it/improvises somehow to get past it. Maybe he thinks that whatever the state of your memory the autocue is the equivalent of backing tracks/drum machines etc, ie it cheats the audience out of a truly live performance?
But yeah, he does have a tendency to turn into an opinionated dickhead at times ...