Imagine being someone reading your post. What are they to think? "Oh, this person says X is worse than Y -- I'll go ahead and take their word for it, despite no justification"? That's them buying into an appeal to your authority.

Now imagine if you'd actually provided reasoning. "Oh, this person says X is worse than Y because Z -- Z is a good point, therefore this is useful!" How different.

Providing baseless opinions is not useful, which is why you got downvoted; and incidentally, it's the exact same reason why you should "care to elaborate".

Obviously not true. You just replied to the counterexample, where I did elaborate on my downvote.