The Oncelers error was not in using natural resources with disregard to the environment because using up natures gifts for pleasure and profit is somehow wrong – his mistake was in not replenishing the source of his product or seeing the use in the surrounding nature. He could have sold Humming Fish as pets and trained Barbalouts as home aids, etc.

The Onceler breathes the same air as the Barbelouts and the Lorax, so it was stupid for him to pollute it just as it was short sighted of him to landscape the forest and ruin the water. It’s the same as in Avatar: cutting down trees to make something people want to have is not wrong. If those trees can download and upload information to and from living beings however – that’s money right there. don’t cut that shit down. Use the “i drink your milkshake” technique and drill for your Hardtogettium or whatever, diagonally.