I think you've changed your opinion because of the way the game was presented to us. The very first trailer was exactly that; a first glimpse into the game. New characters, new places etc. As time passed, Konami stared to show less of the story, and more of the gameplay. As far as I can remember, nothing was explained in the latest trailers, except maybe the E3 one. As far as my view goes, I understood jack sh*t.
I, for one, welcome any kind of footage. I didn't have the chance to get the older Metal Gear games, so I had to start with Ground Zeroes, which was a blast, just short, and a few annoyances that are clearly present because I'm a noob when it comes to the franchise.
But on the other hand, I can understand why someone who's knowledge about the game is vast can be annoyed by the lack of story presentation in any way.
Either way, consider me hyped.