The other annoying thing about the plot was how the game kind of ended with no real resolution. It has the most unsatisfying end for a game. What the hell are the Patriots and how did they come to be? Who is Rosemary and is her pregnancy even real? What happened to Liquid Ocelot? How does the government explain a top secret fortress crash landing in New York City? What is going to happen to Olga's child? None of this is answered, Snake just tells Raiden to live for the future and gives some sappy metaphor about his deeds being his legacy since he can't have kids, and then the game jumps into a lounge jazz song and the credits, followed by one final mind screw.
I think this is one of the many rifts that separates MGS2 lovers and its detractors.
I would say being left with all those questions was precisely the point.
Raiden: Then what am I supposed to believe in?
[...]
Snake: Listen, don't obsess over words so much. Find the meaning behind the words, then decide. You can find your own name. And your own future...
Raiden: Decide for myself...?
How much of the ending was even real was a much debated topic on MGS forums. I think that was exactly what Kojima wanted. He wanted us to walk away with a ton of questions so we could come to our own conclusions about stuff. (Though, personally, I was always pretty sure Rose did in fact exist and was pregnant.)
Then people balked at this and so he made MGS4. Now nanomachiens are the answer to everything....
God I hate that game.
This is part of why I love MGS2 actually. One reason I enjoy fiction is so I can share my experiences with people on boards like these. I love to play a game or read a booka dn then chat with others who have done the same. We share our different opinions and interpretations. MGS2 provided the most conversation of any of the Metal Gear games.
MGS4...well, the only conversation it sparked was "explain this contrived BS to me." There really is no room for debate or discussion.
Anyway, I can understand being dissatisfied with that kind of ending. It' s a very subjective thing.
Still, I think you're short-changing the credits music. I really like it.
Can't Say Goodbye to Yesterday (Full Version) - YouTube