You seem to have missed what led to the reboot of Spider-Man by Sony in the 1st place. Spider-Man 1 & 2 were big successes. They were liked by critics and made money. Spider-Man 2 is still hailed as one of the best CBM's to date. The 1st 2 were made under the guise and leadership of Raimi, who was a life long fan and loved the character. When he started Spider-Man 3 and it was in pre production, the Sony execs stepped in and forced Raimi to include Venom. Raimi wasn't a fan of the character and didn't want him in the movie, but he was forced to include him into the storyline. After the movie was panned, but still made money, the Sony execs asked Raimi to stay on for a 4th. The entire cast agreed to come back for Spidey 4 "If" Raimi was on board as the director and lead on the story. Raimi was to be given control once again. The movie was to focus on the Vulture, but once again Sony stepped in and wanted to turn the character into a young female rather than the classic character everyone knew. After Sony's interference in Spidey 3, Raimi refused to make the changes, and thus walked away. The entire cast followed suit.
The creative differences Raimi had had with Sony was public knowledge, so Sony couldn't continue with Spider-Man 4. Sony now needed to scramble to find an entirely new creative team and cast as much time had lapsed between Spider-man 3 and Raimi working on Spidey 4. Sony needed to continue to release a Spider-Man movie within a specified timeline or lose the rights as they would revert back to Marvel. They had no choice but to reboot it, hence why it was the shortest period ever for a movie to receive a reboot. ASM wasn't as rushed as Fox's F4, but still, the clock was ticking.
