"A way of avoiding or escaping a cost or legal burden that would otherwise apply by means of an omission or ambiguity in the wording of a contract or law." - The American Heritage® Dictionary of the English Language, 5th Edition.
What they're describing is corporations using legal strategies to mitigate their tax burdens that you or I cannot do. Lobbying is legal, but you or I cannot lobby to any useful degree. Big-box store companies build their stores to be short-lived buildings, then will only sell them with a contract that says the next occupant cannot be a big-box store, then argue that since value is determined by what someone else will pay and nobody will pay much for the end of life of a short-lived store intended to be a shop but which now cannot be a shop, so their stores are low value and comparable to empty stores, therefore they shouldn't pay much tax on them. "In Wisconsin, new Gov. Tony Evers says his budget proposal will close the dark stores loophole in the state"[1].
> "Legally avoiding taxes isn't cheating."
Try arguing that you would only sell your houses with a stipulation that nobody can live in it, therefore you should pay the same taxes and rates that an empty lot would pay, and see if you still think that "legal is the same as right and fair".
What you're describing is tax fraud, and that's different from corporations using legal strategies to mitigate their tax burdens.