Here's the practical problem: reaction videos often let someone monetize nearly the entire value of a clip while the person who made it gets nothing. A reaction channel can upload the full original, pause it, nod, and capture ad revenue that would have gone to the creator. Even conservative estimates put a meaningful share of views on viral clips going to reaction uploads rather than the source. That's not commentary; it's substitution. Copyright law cares about whether the new work replaces the original market, and when viewers watch the reaction instead of the original, it plainly does. Normalize that and you shrink the incentive to make the thing everyone is reacting to.

The doorway argument is real but partial. A commuter who seeks out the original is the best case, not the average one. When a reaction upload runs the full clip, plenty of viewers simply stop there, and the creator's analytics never see them. Notice the asymmetry: reaction channels pick winners after a video already blew up, so they capture upside without funding anything. That shrinking incentive is the actual harm, not a camera. Commentary that adds value can quote and excerpt; the theft is the substitution of the whole.

The case-by-case standard my opponent defends is exactly the one I would apply; the dispute is what the dominant format actually looks like. Most reaction uploads are not brief excerpts with analysis, they run the source end to end with a face cam in the corner. Under fair use, the amount used and market substitution are central factors, and showing the whole thing while capturing the audience points against transformation. So the label is not condemning all commentary. It targets a business model that repackages full clips as extra steps. Commentary can quote; this format substitutes.