Whilst talking with Sci-Fi, director Sam Raimi finally answered the question as to why there was all sorts of speculation about other villains such as Hobgoblin and The Lizard making appearances in the second "Spider-Man" early on and why in the end they settled on just Doctor Octopus:
"Well, there were a lot of different iterations of the story, and at times there was more than one villain, and at times there were more than two villains," Raimi said in an interview. "But it all came down to trying to focus on what I felt was the strongest aspect of the film and diminishing everything else so that it could live.
The strongest aspect of the film is Peter Parker [Maguire] and his journey to becoming a responsible young man. So after we had one villain to test his mettle against and to be in conflict with Spider-Man, I found that there were diminishing returns for the second and third villains, since our real story was an interior story, this journey to be a human hero, how Peter Parker battles the problems of being a hero, how he copes. The more villains that we added into the mix didn't seem to make the story richer and stronger. It seemed to diminish [it], in fact".
Thanks to 'Gustavo'
