The people in yellow day glow jackets are simply doing their job... It is part of their job to ensure only people with a valid boarding card for that flight board that aircraft. Remember the security measures at the gate are actually for YOUR benefit not theirs! They don't get on the plane, YOU do. I'm sure you would be the first to complain if security was compromised because they didn't do their job properly. They don't make the rules, they are simply paid (apparently by you) to make sure they are followed. And you having your ID and boarding card ready with a smile makes their job a lot easier and a lot more enjoyable.