Related to his comment:

I love cute cat posts, but I hate a comment section full of “cat” comments and nothing more (or even worse, downvotes on non-cat comments).

It might have been funny the very first time, but now it’s more like bullying. Yes, there might not be much to discuss on simple cat pics, but then you might as well just cut it completely. And if there actually is some validity for a comment (e.g. medical input, or just a genuine compliment, etc), it should not be downvoted just because it doesn’t follow the “meme”.