My issue with the 2nd half of your video is how confused it is regarding "opinion." Even after bringing up Google's common definition, you don't seem to internalize the "not necessarily based on fact or knowledge" part of it. Considering that malleability, you should've examined other definition sources to get a better grasp on what that entails. Because this argument of divorcing "opinion" and "factual analysis" as much possible has some big potholes.
You're not wrong, but I was aware of this simply because the definition of "opinion" encompasses other industries where the term is used. For example, when you talk to a doctor over the phone or for a checkup about your condition, until they actually perform scientific medical analysis, it's just an "opinion". Thus, saying, "I'd like to get another doctor's opinion" has a somewhat different context than in gaming. Doctor's are professionals with knowledge, but even their prognosis can be incorrect, and thus it is an opinion until it is backed by facts (testing, etc.). And even then, the medical testing could prove them wrong, hence why the definition accounts for this possibility of not necessarily being fact. So this Google definition encompasses the most general use of the word "opinion", though it's not entirely unfitting, either. The idea is that even with knowledge, one could be wrong without analysis. Ergo, it's an opinion until it's proven otherwise.
In gaming, this applies rather differently. It's used to define the idea that someone's statements are invalidated by disagreement. As mentioned above, someone could still enjoy a game with a bad framerate, but they see this as means to define the review as an "opinion" because they "still enjoyed this game the reviewer gave a 7 to". And yet, the reviewer could have very well stated and proved facts within the review, also as above: the framerate factually dips during heated action which reduces input responsiveness, thus they enjoyed it less or didn't enjoy it. Using an analogous example: the reality is that Digital Foundry is applying the "medical testing", and thus you rarely see people refer to Digital Foundry as "opinion". Then again, graphics technology IS easier to do this with, but I know there are others that, like myself, try to do the best we can with less resources to show what I say so that it's not just wild conjecture like "this game is absolute trash" without actually showing or talking about WHAT is so bad or what makes it that way. And based on how you broke down what I said, I'm betting you possess the necessary intelligence to see or at least have witnessed exactly what I'm saying, here. There IS such a thing as an unhealthy amount of opinions in a review, but again, not everything in a review is simply "opinion" because "someone disagreed". Yes, there are highly opinionated reviewers, but that's also why I talk about actually reading/watching reviews and trying to understand it, not necessarily agree with it.
Well... sorta? It's not just an "opinion," but a "medical opinion." Our common language has already associated a special qualifier for what you're describing. Even in that checkup or phone call scenario, we infer said doctor is mentally itemizing your listed symptoms (if you're being 100% truthful) based on his years of study & training. In general, I still appreciate how you list these steps out in your first paragraph and I follow what you're saying.
I mean... I don't know about that per se. Seems like you're leveraging that Big Lebowski meme. I've been approached with that response before and I - generally - don't see it as a tool of invalidation. Usually they're applying "opinion" within the context of how I view the story, gameplay, presentation, and so on; it's more about how they view creative decisions versus contesting my framerate complaints. For those that ARE applying that logic to factual statements you can prove via video? There's just no satisfying those types.
You've brought up fair examples of factual analysis, but how will that ever work for those more creative aspects included in games? What if a writer breaks slightly new ground with The Hero's Journey in an otherwise rote adventure? Was it worth disrupting the story's pace to take more interesting avenues? Those are the questions that feel more interesting to see play out with critics & the general audience, and there's no factual answer.
-"There IS such a thing as an unhealthy amount of opinions in a review..."
That's still my hang-up with this response & video. "A proper, professional review will be devoid of opinion as much as possible." But since "opinion" in its broadest sense doesn't irrevocably dislocate "facts" from the equation, this striving for objectivity seems unnecessary. We can operate on a simpler standard. I've always liked Roger Ebert's court comparison: reviews are inherently subjective, but you still have to bring a good & honest case before the jury (audience).