There’s also the difference between disagreeing with the species identification or disagreeing that the individual observed is actually that species (we can’t tell if it’s that species vs it’s another species but I don’t know which), as @cmcheatle described. There are many people who hold both each interpretation. It’s because the text is ambiguous, in one place it implies one interpretation and in another place it implies the other. That’s mainly why these debates exist.
Personally I will add a non-disagreeing genus ID if I think there’s a decent chance the original ID is correct and I don’t see anything to suggest otherwise, but I can’t personally confirm it confidently (someone else might be able to confirm). Since it basically doesn’t affect the community ID it’s pretty much just saying my opinion, and people can choose to ignore it or change their IDs based on it as they will.
I will add a disagreeing genus ID if I don’t think it’s possible for anyone to identify the organism from the image and I don’t see any indication (from description, comments, etc.) that the observer has more information that they used to ID outside of the photos/audio given. The latter is particularly the case for taxa that people consistently trust the computer vision for when they shouldn’t, so I feel like I can safely assume that their identifications were uneducated (which mostly but not always the case, so a text explanation is good).