Firstly, I said "story telling" not creative writing.
Secondly, if there is no objective criteria for what counts as "good" then how can anyone say "Oh, that person is a good writer."?
An author that wants to tell a story seriously has to establish how their universe works and to follow the rules of their universe that they earlier established.
If Oda established that devil fruit users drown when in the ocean but then had them swimming with ease whenever they felt like it only to make them unable to swim every time the plot demanded some instant tension, would that be an act of good story telling or an inconsistency?
If said supposed "opinion" can back itself up with concrete proof then yes it can.
People can like or dislike anything for any reason. Folk can dislike good quality products and like poor quality products. Their personal preference for a product does not magically warp reality and turn a good product into a bad one though.
Like I said previously; consistency of plot, character consistency, quality of character development, lore consistency, quality of world building, quality of fight choreography, good setup and payoff, pacing etc. etc. These are all metrics by which a story can be judged.
If a story had an inconsistent plot that ignored it's previously established in-universe rules on a regular basis, inconsistent characters with no development that often did the opposite of their previously established character traits, inconsistent lore that regularly contradicted itself, poor fight choreography, poor pacing and poor setup for it's payoffs then would it be fair to consider such a series as poorly written?
Is that not exactly what you are arguing for though?
You appear to be against the idea of there being any objective metric by which to measure the quality of a story. If there is no metric with which to measure the quality of a story then how can anyone claim that an author is a good story writer?
If authors cannot be good at story telling then their works really do only become popular "just because".
If I am arguing against popularity itself being a meaningful metric then why would my "ego" supposedly care for how many people agree or disagree with me?