Probably because there's many ways to skin a cat, and it suggests that for many shooters having a rifle that's possibly not "clean to the metal" isn't impacting their guns performance enough to matter (to them), or question if something is wrong with their rifles. Given the hide probably has a large concentration of guys that can shoot with precision gear (granted not in the benchrest world level) it would suggest that for the majority of hide users, most cleaning practices.......are working pretty well. It's kind of like lubes, you'll see guys swear by 50 different lubes which again says to me that as long as you use it, and apply it right, it's probably going to work fine. Even though some might work better than others, it's not enough to make enough difference for most people to notice, and it's certainly not ruining guns. If it was, over the years everyone would be using the same stuff, because everything else would ruin stuff.
If you watch Frank Green and Eric C's podcast they talk about cleaning, and they both use very different methods (everyone should the info in there is gold). Frank's seems to be much less harsh (#9, 40x, no brushes, etc.) and Eric is clearly using some harsher stuff like CLR, Lasso etc. Those methods are pretty heavily at opposite ends of the spectrum, but both are clearly getting good results without barrel damage. They also both clearly are not in the camp of not cleaning the barrels for long periods of time. For awhile I think we often heard so much stuff about how overcleaning kills barrels, that we've made a whole group of shooters that never clean them, or use nothing but a bore snake. Both of them clearly are not in the camp of shooting till the accuracy falls off, because by that time there's so much junk in the barrel, you either have to use drastic measures to get it out, or when you do clean it, the gun will only shoot really well for 20-30 rounds and drops off again cause it's still 95% too fowled to perform when you started and those 20-30 rounds are all it takes to push it too far again.
The other thing is in 2025 when you can get a bore scope that will show you everything in your barrel for $100 or less there's no reason not to own one. We're spending $1000 on bipods, $4000 on optics, thousands on a rifle, $1000 on barrels and $600 on chronos the list goes on, but not $100 on a tool that will really tell you what is going on inside your barrel.