The creators of The Matrix Trilogy had repeatedly state that this was conceived as a "Trilogy" from the start. Although I haven't a reason to doubt that, the 2nd (and 3rd) Matrix fall in the tradition that many sequels of good movies suffer from.
Despite the fact that practically the same cast and crew who created the magnificent first part is here for the 2 & 3 (they shot it back-to-back) the movie quickly loses its spirit.
First mistake is the introduction of many many new secondary characters who might not necessarily needed. And these characters are trying really hard to pose as important without that being the case at all.
Second mistake is the forced philosophy that didn't actually had anything to add to that of the original. The attempt for a recreation of the perfectly scripted dialog between Neo and the Oracle in the original is a failed one. For some, including me, it even destroys the feeling of the original dialog by diminishing its great themes.
Third mistake the (experimental) visual effects this time look completely fake. There is a big fight, shot with something that is described as virtual cinematography, and it's more than obvious that...well..it needs lots of work to be believable.
In conclusion when you are trying for bigger and better there is no guaranty that you will succeed. A common thing in movie sequels. A curse, that struck the second (and the third) sequels of the Matrix.
