Well, I never liked the Spider-Man trilogy, but it seemed like after 3 everyone dumped on the series and little enthusiasm for a 4th entry.
Sony would not have rebooted so quickly except contract was if they didn't do anything with the character for a set time Marvel regained rights (this happened with Daredevil and Punisher for example). Sony saw all that Marvel money and wanted their own universe with Sinister Six and Venom.
I have no idea if that is still happening, but Marvel had massive success and wanted their biggest hero back for Avengers 3. So Sony and Marvel worked out a deal for Spider-Man to be in Marvel films. They didn't want it to be Amazing Spider-Man as be a bit confusing, so yes it will be a soft reboot akin to Ang Lee Hulk to Incredible Hulk.
Spider-Man has been handled poorly, I have yet to really like a film based on my favorite hero, but I hopeful that finally someone gets it right.
