Today in Bad GMAT Logic: Mutual Exclusivity

A student I work with recently sent in this question:

1) The pioneering works of early fantasy authors contain almost all of the plot elements used by modern fantasy authors. Since these modern fantasy authors are merely reusing story elements that have already been written, there is little or no valur in their works.

The argument above most strongly depends on which of the following asuumptions:

As we broke it down, it occurred to me that this type of bad argument is something we see over and over again on GMAT Critical Reasoning. The author assumes that two things are mutually exclusive. If these two things are NOT mutually exclusive, then the conclusion doesn't hold up.

It's SO important to recognize this logic from the paragraph above BEFORE we get to the answer choices, because once we do, the correct answer will seem obvious. Using our scratch pad, we broke down the argument's conclusion and evidence:

C: little to no value
E: reusing

Notice the Conclusion always introduces a NEW idea, something not previously found in the argument. Here, it is the concept of "value." The author is making a claim about "value" based on his previous discussion of "reusing."

The correct assumption will tie "value" to "reusing." What MUST be true in order for this Conclusion to follow from this Evidence? The author is assuming that these two ideas are mutually exclusive. That something "reused" CANNOT also have "value."

Prediction: Something reused CANNOT have high value.

NOW we can examine the answer choices:

A) No work that is based on an earlier work could possibly any contain additional plot or storytelling elements of value

B) Modern fantasy authors must have read the works of early fantasy authors

C) Publishers are willing to promote work that deliberately recycle story elements from other stories

D) Professional reviewers find little of value in the works of modern fantasy authors

E) Modern fantasy authors typically sell many more books that did early fantasy authors

It's pretty shocking how [spoiler](A)[/spoiler] strongly pops out to us as the correct answer once we understand the (1) mutually exclusive logic of the author, and (2) write down a Prediction for what the phrasing of the correct Assumption could look like.

Try this OG question that also has the "mutual exclusivity" logic. Use your scratch paper to break down the argument and write down a prediction.

2) In recent years many cabinetmakers have been winning acclaim as artists. But since furniture must be useful, cabinetmakers must exercise their craft with an eye to the practical utility of their product. For this reason, cabinetmaking is not art.

Which of the following is an assumption that supports drawing the conclusion above from the reason given for that conclusion?

Do you have the Evidence + Conclusion + Prediction written down on your scratch pad? Before proceeding, double-check! Write down "ABCDE" so you can use process of elimination. Okay? Ready...set...answer choices!

A) Some furniture is made to be placed in museums, where it will not be used by anyone.

B) Some cabinetmakers are more concerned than others with the practical utility of the products they produce.

C) Cabinetmakers should be more concerned with the practical utility of their products than they currently are.

D) An object is not an art object if its maker pays attention to the objects practical utility.

E) Artists are not concerned with the monetary value of their products.

The correct answer must be [spoiler](D)[/spoiler].

C: C is not art.
E: Furniture useful/practical.

Prediction: Something useful/practical CANNOT be art.

The author is making a bad assumption that something useful cannot also be art. That "usefulness/practicality" and "art" are mutually exclusive.

Please feel free to post other arguments that contain similar logic below!