It's rather complicated. The lumbering while under Thrall was ok and in that era I would side with the Orcs, they need their materials after all and back then they just cut down what they used.
Under Garrosh however it became more about pissing off the Night Elves, cut more than they needed and letting it rot. That's just plain stupidity.
Now if only the lumbering would be cut back to what was needed.