I think these opinion columns pretty much capture the debate:
George Wuerthner: “Thinning doesn’t help fight wildfires”
12 respected foresters: “Effectiveness of fuel treatment on wildfires”
George Wuerthner: “Put focus on home environments”
I think Wuerthner’s main point is that fuel treatments work best in circumstances where they are least needed, so there’s not really much of a return on the investment.
I think it’s also fair to say the that the question of whether a fuel treatment is cost-effective (in a broad sense of the term) depends on where it is, and particularly the likelihood and value of resources being protected or impaired. The second article asks a good question: “what purpose ‘chronic objectors’ have in slowing this beneficial work.” It shouldn’t be hard to identify the differences between those projects challenged and those that aren’t. My guess is you’ll find the former tend to be in undeveloped areas or old forests or lynx habitat and the latter are not but are closer to communities. In any case, if you give the Forest Service a blank (litigation-free) check to pick whatever areas they want there is no incentive for a full accounting of the costs and benefits.