I really don't understand why people get so hot under the collar, it takes a few seconds to show your boarding pass to the crew on the plane, and as my grandmother used to say "Manners cost nothing".
Yes, I am a frequent flyer, yes, having idiots in front of me who cant find their boarding cards at the plane irks me, but hey, we can't all be perfect. It doesn't hurt to smile at the crew and wish them good (morning/afternoon/evening) as you board a plane.
Perhaps we shouldn't let grumpy people out of the country, brings down the reputation to the outside world!