[NonNefarious]

That's not the point at all. The Magnuson-Moss Warranty act arose out of scams perpetrated by car manufacturers, who tried to invalidate warranties unless you bought "Ford" oil or "Chevrolet" tires.

This goes beyond third-party repairs. The law says the company can't invalidate a warranty even if the user MODIFIED the product in question, unless the modification caused the issue for which the customer is seeking warranty service.

So the problem is this attempt to invalidate an entire warranty because of irrelevant actions the owner might have taken.