I'm sorry, but I think this is a fallacy. If you enjoy a game then its doing a lot of good things. Conversely if you say "wow this game does lots of new and great things" and its not fun, than that game is doing something majorly wrong. Video games are about entertainment. Any game that is entertaining is doing something majorly right, even if you can't put your finger on it.
The problem with your statement is that both "fun" and "entertaining" are 100% subjective. Sure, they always pop up in reviews, as it is hard for any writer to draw the line there, but they are not criteria that an objective review should use too much for a rating. They are useless in stating if a game is good or bad, they just tell if you liked it or not.
Is the Codex review fully neutral? Surely not, but surprisingly much at the same time. It is so easy to bash Fallout 4 for so many things, but Bubbles actually took the time to explain. Commendable, seeing how much he suffered through it lol
Almost nothing in there can just be put away as opinion, even if some
foolish fanboys would like to think so.
Graphics can be analyzed objectively (by not judging the art direction itself - that would be opinion - but by how well it was achieved).
Same is true for sound, same is true for stability, performance, UI, etc.
And yes, same is true for game design - which is without a doubt the most important part. I'd include storytelling here as well. What did the designer(s) set out to do? How well did they achieve it?
In the case of Fallout 4, they failed at pretty much everything they set out to do, game design wise. As the review showed very well.
Does that mean the game is unenjoyable? For some yes, for some no.
It doesn't matter in qualifying the game as good or bad. And it shouldn't, or we would soon say games like Angry Birds or CC Saga are the best games of all because of how many people enjoy them.
All of that doesn't mean that opinions should be banned from being stated on sites, of course. It would just be nice if opinions were stated as such more often, and left out of actual reviews more often…