I think one clue into NPS's motive in trying to accommodate those larger boats with some sort of program like this and justifying selective pinning is revenue. Seems obvious. I'm a boat renter, not owner, and so I've been following that market for decades.
In 1992, there were only three sizes of houseboats you could rent - 36, 44 and 50 feet. None were luxurious. All had basic amenities, nothing more, but it was good enough. No air conditioning, not even swamp coolers, very much more like camping or a very basic RV set up. Old welds, very basic small refrigerators, etc. And that was fine. And those boats were pretty cheap.
Over the years, they upgraded the amenities, but mostly, they greatly increased the size of the boats they rented. And the overall quality of the boats. And charged a lot more for them. I imagine they were responding to the market, but they were also trying to draw customers with more money, and yes, the market was there. First it was 53-footers in the late 90s, eventually boats larger than that, and one day they introduced the 75-foot Odyssey, so outsized it caused a double-take when you saw one. In the early 2000s, we still rented the smallest boats they had (which were still cheap), but we noticed that they would start to cannibalize those boats for parts (like mattresses, or stereo equipment) to put on the larger boats when one of those large boats had a problem. Aramark admitted as much when I had conversations with their rental staff when a problem arose on our smaller boats. Again, they were cultivating or responding to a luxury market. The one with lots of extra money.
In the past ten years or so, the smaller boats have fallen into a state of uneven repair (very hit and miss), and though I can't speak about the bigger boats, I imagine those are doing somewhat better. In any case, the rental fleet now includes a much larger proportion of larger boats than it ever did in the past, and by that I mean boats over 60 feet long.
Today, a 75-foot rental in peak season costs somewhere in the neighborhood of $13,000 per week. A 46-foot "economy" boat (the smallest houseboat they now rent) can be had for under $3,000/week, less than that outside of peak season. So it is very much in NPS/Aramark's interest to rent as many of those 75-footers as possible, which means they need places for those to camp. Which leads to things like beach bags, and blind eyes to consistent pinning practices.
There is a market for those huge boats, of course. People rent what they want, and obviously NPS is trying to accommodate them. But I never thought Lake Powell was a good place for those behemoths, because the best places to camp (very small nooks and beaches among the slickrock domes) are not practical or even possible for those boats.
Maybe there's a good reason the rentals were all 50 feet or smaller three decades ago....
