Why is this supposed to be something that works in favor of those who use box mixes? It really does not do them much of a favor. The argument is not scratch is greater than all--that no matter how poor a scratch cake is, it will always better better than a box mix. Maybe there are some, what were they called, "militant" scratch bakers that will hold this view, but those individuals will just look ridiculous.
A well made box cake is better than a poorly made scratch cake? And? Taco Bell is better than burned food from a restaurant that is claiming to serve authentic Mexican cuisine, that means nothing when that restaurant cooks the food perfectly, using the freshest ingredients. McDonald's apple "pie" will taste better than poorly prepared pies from the local bakery, it is no contest when that bakery bakes their pies using a well made-crust and fresh apples.
The point is this--justifying the quality of a product by comparing it to a poorly prepared product does nothing for those that bake from a box. Because by not insisting on the quality--that they are as good, if not better, you already concede the point to "militant scratchers" that believe when all else is equal box based cakes (even those that are doctored) are simply inferior. Thus people who bake from boxes should never endorse this idea because when it comes down to it those arguing that scratch > box are presuming that they are well-prepared not poorly prepared.