"It's the travelers who don't fly often who take awhile to get through. They are bringing everything but the kitchen sink."

This in my view is the main reason for elite lines...The occasional traveler who can't read any of the signs or listen to any of the announcements about what can and cannot be brought through security. And has no ability to remove metal/laptop/shoes/jacket etc. in a timely fashion.

Your typical FF knows how to get through the checkpoint quickly and efficiently (except when some TSA employee decides to enforce some made up rule).