Not sure if this line of argument is being helpful. It’s skating close to ad hominum.
@typoclerk, To clarify my position, and perhaps several others, I’m not opposed to actual cairns. And I understand that not all cairns are old and culturally significant but can still have a valid purpose. It’s the rock piles that pollute busier natural areas more and more, especially stream habitats. They are also called cairns by some. I looked at your profile and saw AMC and White Mts. Maybe your experience is mostly real cairns, treeline comes pretty quick around there. Where I am, we use paint, metal, and plastic for trail blazes but mostly can just follow the worn path. Cairns are not tradition here.
The one I took apart Sunday was was started on a lichen covered boulder probably within the last 2 weeks. It was on an obvious footpath. I released the lichens from their roof and placed the larger rocks back into the leaf litter holes they came out of. I’m not really angry when I do this, mostly disappointed.