I guess it's that the game is really just a movie--the player's agency in the game is really just there to press play and pause when requested.
It's slightly more than that, because you (the player) have control over the character. It may be different watching it than actually playing it, but it's just as much the player's struggle for survival as it is the player character's. I don't think that it's a perfect game, but it's mechanically sound, functional, or above average, in all areas. It's the presentation, and experience that takes it to another level. How many times have we here complained that writing in games suck? How many times have I bitched and moaned about player characters not being older people with real problems, worries, and fears?
On one hand it's safe in much of what it does (every piece borrowed from Uncharted), but on the other hand it really is outside what's considered normal, particularly in a AAA game. I personally also think that presentation does matter, and it certainly has that. The dialogue, and voice acting, the overall presentation are what I truly think makes the game special.
And with all that said... A middle-aged main character portrayed in this manner makes me happy beyond belief!
Edit: I guess my statements sound contradictory, but it really is a movie game, that's also more than that. Underneath it all is actual solid gameplay, the sneaking can get a little frustrating, and I thought it sometimes just broke, until I realized that it was me stepping on glass, or dropping an empty magazine that was alerting enemies.
Ultimately I think that video games as a whole are better for having a game like this. But I also don't want every game to be like this. Just like I don't want every movie to be The Professional
, or every book to be The Road.