Yep, I have never not waited at least a few minutes for someone to come over and pat me down. Once I waited 10 minutes at SFO, and I had to ask the same TSA agent who was nearby multiple times to get someone. I was in fear the whole time that my laptop, just waiting around on the other side of the conveyor belt, might disappear.
And then you get to watch the employees' form of protest as they chit chat for a few minutes before heading over to fetch you.