Reviews are worthless for the most part, unless you know what type of person the reviewer is and what kind of tastes they have so you can draw parallels with your own tastes. That kind of mindset will make you miss out on great experiences. If Nier is anything to go by(which I personally havent had the chance to play yet), mainstream reviews are worthless, for my tastes atleast.
OK, I'm very late to this discussion but I couldn't just overlook this. Your example of why reviews are 'worthless' is a game that you haven't even played...yet somehow you're completely confident it was mistreated by 'mainstream' reviewers.
Let me tell you something: I've played Nier. I loved Nier. It was one of my favorite games whenit came out. But I also recognize that it is an extremely flawed title and not everyone is going to like it. For everything point it succeeds at I can list half a dozen points where it stumbles. Honestly if I was going to review Nier I would probably give it about a 7/10, which coincidentally is pretty close to its Metacritic average. This is despite the fact that I love the game, which I do. I don't consider these statements to be contradictory. Loving a game despite its flaws does not mean you have to ignore the flaws.
I think the real problem here isn't reviews as much as it's people acting like a 7/10 is a horrible score that means a game is unplayable or something. There is an awful lot of whining out there whenever a game somebody like didn't get a 9+ or whatever. At least from my perspective that seems to be the real origin of the whole "reviews are worthless" attitude. How about you stop obsessing over scores and read the actual text of the reviews in question? I generally find that to be far more enlightening (and in the few cases I've found when the criticisms had no weight it's generally self-evident).
Mainstream reviewers lack consistency, besides I dont just look at the scores, I read the actual text and I find many of their complaints to be inconsequential or not actual negative points or I simply disagree, many reviewers overlook gameplay elements and fail to grasp the most basic of mechanics or even storyline elements(ahem, Spoony's FF XIII review)(They are working under big time limits and some might not even be fan of the genre of the game they are playing, one big example is how Daemon Hatfield from IGN complained that Ghost Trick was too wordy and had that as one of the game's big flaws, Are you fucking kidding me?! IT'S A FUCKING VISUAL NOVEL). Im not trying to generalize here, all im saying is that for me personally reviews are mostly worthless, I didnt say reviews were fundamentally, objectively worthless, if you find value in them yourself more power to you. And like I said originally, if I know the reviewer's likes and dislikes I can more easily draw parallels with my own and find more value in their reviews.
And usually when one aspect of the game is so amazing, the other small design quirks are easily forgotten in the big scope of things for me.(case and point 999(a game I would easily say is 10/10 even if it has a few flaws) for instance).
Dont forget that we also live in the age of Hyperbole where ocasionally small flaws are blown out of proportion.
When I say reviews are worthless Im not talking about the score, Im talking about what is said obviously.
Oh also, I can give many examples of why reviews are mostly worthless(FOR ME) of games that I actually played(I used Nier as an example because it's more universally loved than any of my examples) - FF XIII, XIII-2, Any Xenosaga, Chrono Cross(not mainstream reviews but general internet opinion), etc... My point still stands, it's always better to judge things for yourself based on your own standards, likes and dislikes. You can use reviews and stuff if you want to determine if the game is worth playing but I am at the point where I can look at a game, see some gameplay videos and stuff and see if I will like it or not, it's not hard science but atleast it's better than maybe losing out on an amazing game just because the internet doesnt like it. Hence why I think the general consensus can go fuck itself, I would have missed out on great games if I blindly followed it.