Burning isn’t always bad. Prescribed burns are an important part of modern forest management. They are one way to reduce the fuel load, without harming mature trees. There haven’t been enough prescribed burns in recent years, due to opposition by environmentalists and NIMBYs. We should “let it [prescribed burns] burn”.
Where there’s been too much fire suppression in the past, and fuel has been allowed to build up; the inevitable fires are devastating. Among other things, mature trees are killed. We want to avoid getting into a situation where we have no choice but to “let it burn” like that.
I’m not talking about prescribed burns, which I agree with you are important.
What I was talking about was the policy level concept, pushed by leftists, “Let the Fires Burn.” It means not doing the firefighting part of management.