I'm not even a big Metal Gear story fan and it was a monumental letdown. It had lots of tiny, cool implications, but from such a bombastic series that's not nearly enough of a reversal to counteract the loss of so much craziness.
I also think it wasn't helped by the world being so barren. People talk about it like an open-world game, when it's really just a sandbox game with a bunch of missions to choose from in an almost entirely linear order. The "open world" aspect of it is just that sandbox with jack shit going on in it when not on a mission.
It's kind of a big distinction, a sandbox is where you can use a lot of tools to accomplish your goals or just muck around for fun, and MGSV does that beautifully, an open-world game is where you have a "living" world and can completely ignore main stories, side stories, etc and just have a great story to tell about the quests you did and the people you interacted with. The only character interaction in MGSV outside of Mother Base is extreme violence.
Anyway, seeing that what was clearly going to be the best mission in the game to justify the building of Mother Base was cut was a punch to the gut, seeing that there might have been a third and final chapter to really ramp things up and finish the story as a whole was a punch to the nuts.
The game never grew into anything more than "This is fun to play." which is cool, I like my games to be fun, obviously, but... I like to have more than that, too.
