I agree that it's passengers who are primarily to blame. Ryanair makes its rules clear - they're printed on the Check'N'Go boarding passes, for heaven's sake! The problem is that too many people think the rules don't or should not apply to them. Same with arriving at the airport after the minimum check in time and demanding to be checked in etc. (or, for that matter, keeping to the speed limit when driving etc., etc.).
I do feel sorry for agents/cabin crew at the gate but Ryanair should not give in on this one.