They refer to 'thousands of gallons of chain-and-bar oil... carried into the forests' every year Is this quantity significant?
Consider that chainsaws are only one of many polluting tools that people use in forests, e.g., snowmobiles, generators, of course cars. There are many non-petroleum pollutants as well, like lead ammunition and trash. I believe it’s a useful practice to reduce harm from each of these as much as possible. That reduction might come from banning them outright to small changes like using vegetable oil as chainsaw lube.
The opposite approach is requiring harm to be demonstrated by each of these small things in order to encourage or require change. This has gotten us roughly to where we are now, with much wilderness in the country despoiled by human practices.
All of us are better served by being conservative in this context: by intentionally doing the least harmful things possible, and looking for ways to improve.