I'm beginning to wonder exactly why the world thinks it continues to need superhero movies. I mean, they can be fun, to an extent (like the first two SPIDERMAN movies), but mostly, they're just stupid.
SPIDERMAN 3 falls much more into the stupid category than fun. The first half is entertaining enough, but it changes gears too quickly and bogs down with plot. What is it with superhero movies that they can't be satisfied with one coherent plot, and instead they insist on three unsatisfactory, incoherent plots? (See BATMAN & ROBIN, for example.)
Attempting to explain the plot of SPIDERMAN 3 in less than its running time is almost impossible. Spidey splits into his own evil double, which then moves into someone else. That would be enough for most movies, but he also learns the man who killed his uncle is still alive, and has become a super-villain made of sand. That would be enough for TWO movies!
BUT WAIT... THERE'S MORE! Now how much would you pay?
His old best friend has inherited the role of Green Goblin and is back with a vengeance, literally, trying to kill him.
Please, when you're writing a movie, try to stay focused.
Then there's the problem of tone. Bill Campbell's humorous cameo I can forgive, but the whole "Spidey walks the streets of New York as a gigolo" montage was just stupid and stopped the movie. Instead of being comic relief, which could have helped, it turned it into camp.
Stick a fork in this franchise.