They seem to want you to sign up for Global Entry - which ends all of the harassment, for a fee. If I had to guess, collecting the fee is a big part of the game.
Global Entry allows returning US citizens to be treated with the same respect other countries give to their returning citizens. You just have to pay the bribe, like they do. :)
Global Entry has a “random selection” aspect too. Plus the fee is a pittance, couple hundred bucks good for ten years - bigger hassle is showing up for a face-to-face interview.