In the latest issue of Entertainment Weekly, The Amazing Spider-Man director Marc Webb discussed the transformation to the classic mechanical web shooters, present in the original comic book series, from the genetic web-shooter.
In the Sam Raimi directed movies, Spidey was genetically given the webs, but in the comic books, Peter Parker made the web-shooters with a mixture of chemicals. But, it was said to be “too advance” for “geeky” Peter Parker to manufacture in Raimi's movie.
“We made a very conscious decision to go back to the mechanical web-shooters,” said Webb, “and I think the fans will appreciate it.” I guess it all depends on what he meant by "fans."