Game? Yes. Final Fantasy game? Not so much.
Metacritic lists it as the joint eighteenth-best Final Fantasy game. I don't think it's unreasonable to expect a new Final Fantasy to hit the top five every time and top ten should be a given. Less than that and the game is surely not up to anyone's expectations.
Now, of course, this is also opinion. I happen to agree with it. A lot of others do too, and I say that not because I'm trying to speak for the majority, or because I look at what people write on internet forums (I don't), but because the physical evidence shows it. Second-hand copies of the game are plentiful and available at incredibly low prices for a game of its age (£5 to £10 here in the UK). Compared to other Final Fantasies and other RPGs released in the same year, this shows that a larger proportion of folk who have bought the game consider it near-worthless.
If you thought that the Paradigm Shift, Crystarium, Item Upgrades and Cie'th Stone missions were good game mechanics then good for you. From the perspective of past Final Fantasies (and present if we include FFXIV here), my opinion is that they are weak and uninteresting, like the characters and the plot. I love the style, the graphics, the music, the lore/bestiary and the UI, but that's not enough to make me want to play it for 100% completion.
As mentioned briefly before, FFXIV is looking to tick all of my 'expectation' boxes and set the FF series back on track, if not at the least for me, hopefully for all fans of the series. Its current Metacritic position at #60 (yes, 1.0) will hopefully be forgotten as ARR takes the #1 slot until the release of XV, and maybe for some time after.
I'm fully aware that you have six years' experience in the industry, but in this thread and others in recent weeks, you would do well to consider your own posts if you percieve others have put across their opinions in this particular way.