“Doesn’t make much sense, they usually mark trees that are to be cut down, not the other way around.”
It depends on the type of cut you are doing. If the trees are thick and you are taking out a lot of them, it’s a lot easier to do a leave tree mark, i.e. cut everything except what’s marked.
After reading the article this appears to be a take tree cut. He was probably either, as someone posted above, trying to get the loggers in trouble, or trying to reduce the fire hazard near his house.