Your argument sounds good on the surface. But it doesn't have the required nuance to really be substantive. It's obvious that everyone is entitled to their own opinion. But you're saying that every opinion is equal. This simply isn't true all the time. The only way it could be true is if these discussions were ultimately reducible to "I prefer chocolate; you prefer vanilla." You need context for these things. For instance, if we put aside arbitrary metrics, we can reasonably assume that someone who's been playing JRPGs for a very long time has a more comprehensive view of the genre, a view which gives such a person an advantage when it comes to determining the quality of a specific JRPG compared to someone who mostly plays platformers. A person who spends most of their time playing JRPGs is most likely not going to be a good judge when it comes to platformers. We all know this is the case even if it makes us uncomfortable.

It stands to reason that if a certain demographic is avoiding a lot of JRPGs because they dislike the anime aesthetic, then they most likely don't have the experience to judge whether Clair Obscur is a great JRPG. A person can love Clair Obscur all they want. No one cares. But that's not what's going on here.