Obviously the reason is because you're pulling boats. Boats & RV's all go into the same "private/RV/not for hire" non-commercial use and they don't actively persue those people, although they should because unlike commercial drivers, few have any formal training. I see people walk into an RV rental and rent a tandem motor home with an CAT pusher with a standard driver's license. Stupid.
If you tried pulling 14-16K of dozer, bobcat, backhoe, etc. behind your work truck, you won't be doing much "blowing by" cops in PA. I get pulled over with well maintained equipment for routine inspections, first thing they ask for other than license is registration, which makes it easy for them to tell if you're over GCWR by manufacturer or by what you're towing.
You're not gonna get a weight class 5 or 6 sticker on a 1-ton pickup in PA unless you're the governor's son in law.
Ohio/Indiana might be a different story.