In the PNW forests I worked in, thinning was something logging companies paid the national forest for the right to do. Thinning was just another logging contract.
This meant that the forest managers were under a lot of pressure to provide thinning contracts, which would be income for the forest service.
It also meant that the thinning was done by companies who didn't have any particular interest in conservation, and were motivated by profit.
It's true that an old growth forests the trees rarely burn, just the underbrush. And in young forests the trees burn.
How to get from one to another is difficult. For one thing, the logging practices of the past couple hundred years have destroyed the soil, and most of it has washed away. When replanting, it is difficult to even find a pocket of soil to put each tree in.
It's interesting that you find the thinned forests pleasant to walk in. What sort of ecosystem did you grow up in? Are they more like the forests where you grew up? I find them extremely creepy and I basically feel like I'm walking in a Walmart. Widely separated young trees are not something that occurs in nature in the PNW.
