If I remember the Matrix Revisted accurately (the "Making Of" DVD for the original Matrix), the entire trilogy was written before the first film was made, and that they made the first film with the intention of it being the first in a set of three films.
I do agree though that adding sequels just because first film did well can lead to some awful screw-ups, though this isn't awlays the case (ie, Terminator 2).
If I remember the Matrix Revisted accurately (the "Making Of" DVD for the original Matrix), the entire trilogy was written before the first film was made, and that they made the first film with the intention of it being the first in a set of three films. I do agree though that adding sequels just because first film did well can lead to some awful screw-ups, though this isn't awlays the case (ie, Terminator 2).