What "larger pickups" have lamps, from the factory, that measure more than 54" from the ground to the center of the lamp? Yes, people who are installing lift kits more than 6" and the tires that then fit as a result of the lift (and usually the help of a BFH) are likely to raise the lamps above this maximum height. But that is not the OEMs fault, or a sign of their lack of compliance.
Additionally, as you say enforcement should be increased for "uncovered lamps." I would pay Very Good Money to listen to an argument on the side of the road with some state trooper that driving around at night using a pair of bucket mounted sealed beams, and trailer turn signals is something you shouldn't be ticketed for, because you disabled your now-too-high OEM headlamps (which due to their complex shape and mounting tab positions do not allow one to lower them easily, if at all).
I lifted my old 4runner. Because I built a winch bumper, I had to move the turn signals. I made sure that my height amd mounting position was fully compliant with my states inspection handbook, and neither was blocked from view. Yet I received more than one ticket for "removing/disabling safety equipment" because a troopers word is law on the side of the road, even if the actual law is printed out in plain black and white and in the hands of the driver. Enforcemenr comes down to an understanding of the reasoning for a law. There are laws that are so stupidly written, that enforcing them would be harmful. Just for vehicle lighting laws, in PA, there is no referenced standard for what constitutes a "fog lamp." Anything goes. However both fog lamps and driving lights, which serve two extremely different purposes, must be aimed identically. Even if a real fog lamp were to be mpunted and used, the "legal/compliant" aim would result in blindimg glare for oncoming traffic, and the same aim for the driving lights would result in far far too much foreground light, reducing the effectiveness of both the driving lights and the OEM highbeams.
The law is a fickle thing, usually extremely poorly written by people who are the least qualified to write it, and enforced by people who usually don't care outside of personal axes to grind.