It's difficult to articulate. I guess it just 'feels' too close to DOS and so it cancels out the nostalgic feeling people want to feel. It doesn't throw them back to the original games.
I'm sure there are many small differences that are not a problem by themselves but the accumulation of them is enough to make it feel like DOS rather than BG.
I think this is actually the best concise articulation I've seen on the matter. I haven't played EA, but am very hyped for the game... But as a BG fan, I worry it might not feel like I'm playing a BG game, even if it's a great game on its own. I don't think I've seen a single review that says "yes, this is a great BG game". The problem is that the "feel" of a game is incredibly hard to capture, especially in a game with such big changes to the original saga. Many of these changes I like, but, as it's been said, they accumulate and alter the "feel", even if there will be significant plot connections.
