You see, a video-game most vital point is the gaming experience. Rockstar is sacrificing substance (the actual gaming) for the shadow (immersive story).

While this is not true for most of people, you should understand that no matter how good your story, if your gaming isn't good enough, people will not enjoy, look at the original Nier, superb story and music, yet questionable gameplay makes that few people actually played. So, you have Rockstar that decides to enhance the character story and great limit the gameplay in favor of the immersion, contrary to everyone else, but they just don't have a story that good enough to carry the rest of the game (think a visual novel), look at the whole cast of one cliche characters outside the main cast, and even if the did, it would be hard to surpass a story in a specialized book/movie/series/etc, because they are limited of how much they can do in a video game.

Then you have a game that limits himself because of a history that's not that worthy.