Sickness and bad conditions usually slow growth down.
In tree farms almost all the trees are in bad condition. The low biodiversity creates a low quality environment. They catch fire very easily. It's low quality wood that ends up in a landfill (and then in the air via rotting) within a few decades.
Eventually a tree will get sick and die. The most ideal situation would be to harvest the tree when it's dead. I would think there could be a businessmodel that maps dead trees and extracts them from forrests for high quality old growth wood.
This is not about "stubborn environmentalism". Although I do agree with you that some environmentalist ideas are a bit short sighted (like dismissing all nuclear options without weighing the properly), it is generally based in science and research. The anti-environmentalist side are usually mostly based in money and corporate interests...