What people most loved about the game was the hype at launch, the CG graphics of the cutscenes and the feel of a breathing Midgar.
They are basically saying "remember those amazing trailers, now we can play with graphics 100x better than that!" They are catering to a long dream of living that experience in its fullness. In fact, most people will be satisfied with just playing Midgar, while hardcore fans will probably get into the later parts much more.