I think this stems from earlier answers that berated question askers for not doing an image search or simple google search - such scolding clearly isn't allowed.
Is the Stack Exchange not also harsh on questions that clearly have not shown any prior effort to research the problem? It is in my opinion that these easily searchable image request fall up the same lines.
However, we've now swung too hard to the other side, and answers which include any explanation as to how they solved the puzzle of figuring out the anime from hints in a question are being targeted for comments, downvotes, and edits.
Usually when someone's looking for something that's on the tip of their tongue they're more concerned with what it is their looking for, rather than what something did to go about finding it. For identification question, it's expected that we only tell them what it is they're looking for and why we believe this is what they're looking for. If the OP would like to know how we found it, we usually tell them what the methods we used to find it, but rarely is this expected.
Is it, or should it be, policy to force users to strictly limit their answers and include no other explanation or information on how they solved the riddle, based on the question's hints?
We don't really like forcing someone to do something they don't want to, but we do reserve the right to reject content that's below a set standard. We only give what's needed to the OP in answer, because we anticipate that it's all that they're looking for. Why bother explaining to someone something that they have no interest in hearing?