I agree. There are some trails that are poorly marked. Other times, spring snow-melt will create what looks like a trail, misleading people. Flash floods can wipe away whole sections of trail. I've had fallen trees, yet to be cleared by trail maintenance, obscure the actual trail and I end up following an animal path or an otherwise deprecated path. Hiking in snow presents yet another problem. There are several places I've hiked above the timberline that are wide-open scree fields with no discernible markings. There are plenty of "unmaintained" trails -- they're on maps, but not the beneficiary of any upkeep. Even with a flashlight, hiking at night in thick cover can be a real challenge at times. Many trails are well marked, but there are many instances in which they're not.
>> If you're backpacking through unmarked wilderness, you need a navigation system, and you know you need it. That's 0% of people to several significant figures.
I semi-regularly backpack through unmarked wilderness with no navigation and no map, and I have friends who do as well. But as you said, perhaps I'm in the 0% to several significant figures.
> I semi-regularly backpack through unmarked wilderness with no navigation
If this were true, you'd be lost. I'm including things like "keep the mountains on your left" in the category of "navigation".
The people complaining about forests are correct in that regard -- in a forest, you can't see the mountains, the sun, or the stars, and getting lost, unless you have very good training in forest navigation, is pretty much inevitable. (If there's a river, you _can_ still see that.)
>> If you're backpacking through unmarked wilderness, you need a navigation system, and you know you need it. That's 0% of people to several significant figures.
I semi-regularly backpack through unmarked wilderness with no navigation and no map, and I have friends who do as well. But as you said, perhaps I'm in the 0% to several significant figures.