An ecologist would readily note that we do restoration work on damaged environments on a regular basis, so it is clearly possible to undo some level of damage. They'd also likely note that consulting an ecologist as part of the process might limit the damage in a way that a bunch of Harry Potter fans making a pile would not know.

Not doing anything might indeed be better for the environment alone in isolation, but has to be balanced with other considerations, like the benefits of a power cable carrying clean power from wind farms to replace coal.

It is also entirely possible to plant native, locally appropriate seeds in a reasonably natural fashion. I am obviously not proposing a layer of lawn sod.