It's true that nobody comes to the park specifically for the trees. However, a lack of trees can significantly hinder a park's atmosphere. For instance, the back side of Dollywood pales in comparison to the front in terms of park appearance because of the shortage of trees.
I'm not knocking SDC on their construction site as I can imagine the cost of construction being much higher if they wanted to save a few trees, but if the setting does not return to its wooded feeling, it can potentially harm the atmosphere of this area, especially for Thunderation.