Here's three reasons why:
*
First off, Sam Raimi has gone soft as a director, it happens sometimes when you have kids. I can't believe that this is the same man who made a tree rape a chick. I compare it to Eddie Murphy's career after he starting having kids. Remember when he was
RAW, now he's talks to cute talking animals and crap?
*Also, the main reason is Marvel, they just simply don't look out for Spider-Man's best interest, or work with the best people who can elevate their Spider-Man property, they only look out for making what money they can off of him.
*Not to mention, you have to have a director who both understands what makes Spider-Man and his universe tick, along with handling the ramifications of combining fiction with non-fiction in a realistic way. James Cameron (T2/Aliens/Abyss) is absolutely brilliant at this, so is Ridley Scott (Alien) and the guy who directed The (original) Predator, The (original) Matrix is another swell example. I'm not saying these people should or would direct a Spidey film, I'm basing this only on their said movie(s).