That's certainly a typical narrow viewpoint based on inexperience. Simply because you don't have the experience to be familiar with this type of technique, don't condemn it.
It's not a procedure, it's a technique, and it's quite legitimate. I've used it, and been a part of a number of operations that legitimately did so, ranging from single engine Cessnas operating off dirt airstrips to large four engine airplanes operating in busy terminal areas.
It's standard practice in many ag airplanes, which is a very legitimate use; lowering flaps upon touchdown of the main gear permits lowering of the tailwheel, which permits application of reverse thrust. Reverse thrust, as you might guess, reduces landing roll, reduces break use and wear, permits faster turnarounds, and enhances control, particularly on short runways.
When departing from a rough field, particularly one with loose chips, lowering flaps well into the takeoff roll reduces damage to the flaps. It's a legitimate, and appropriate technique in several types of airplanes I've operated...and far from a "made up procedure."
When landing on ice with a crosswind, judicious use of flaps while on the runway has often proven a useful control technique. You might be shocked at the concept of raising and lowering flaps in a turn, but to avoid a stall-spin while maneuvering at 75' in steep turns, which is often done nearly or to the stall buffet, it's necessary. Lower the flaps as one rolls into the steep turn, take the flaps out as one rolls out...appropriate technique given the type of operation.
You make an assumption regarding part 23 airplanes and the use of flaps throughout the landing roll, and you overestimate the effect of flaps during the rollout. In fact, as the airplane slows, the aerodynamic braking and drag provided by extended flaps is largely negligible, whereas braking is not...and raising flaps to enable better control on a soft or slick surface, and more effective braking on nearly any surface, is a legitimate, commonly used technique. Apparently just one outside your realm of experience.