This is a good point. I think art is a good analogy. Obviously, there isn't cut and dry criteria for good art. But, if you narrow down your scope, you can start to define some guidelines. Like, good realism, or good impressionism, they have general guidelines that you should follow. Similarly, you can't define the rules of a "good rpg", but you can get close to some guidelines if you narrow it down to a good "rules-lite political intrigue game", or a good "tactical dungeon crawling game"
Honestly, I think this is the key. Like, I'm not a fan of games that make choices for my characters, but I can still kind of tell the difference between when it helps characterization and when it's just obtrusive. Or like, I don't like the resource system in Fate, but I get that there are people who just don't care about that.