Sonic 06 was never close in killing the series or it's reception.
Sonic Boom was never a spin-off, it was always planned to be a reboot of the franchise.
Even if IDW dies, it doesn't mean the characters like Surge or Whisper will be vaulted as SoA and SoJ has expressed interest in using them beyond the comics.
Sonic 4: Episode one was loved by fans and critics at launch. The hate for it was from a small minority on Sonic Retro until Cypershell made it widely known why the game isn't good.
Archie fans actually loved humans and never pushed them away.
Sonic X-treme wouldn't have saved the Saturn, had the game actually came out.
Yuji Naka isn't some evil asshole, he wanted to make sure that the Sonic series was up to quality standards.
Lost World was never meant to be a Mario Galaxy clone. It's a spiritual successor to Sonic X-treme and it was originally meant to be a Classic Sonic title.
Shadow was always planned to be part-alien since Heroes.
The Sonic Rush dualogy was originally non-canon until Generations decided to make them canon. The same applies to the Advance trilogy and Battle.
Silver was always planned to be reintroduced into the canon with Sonic Rivals. Akin to Shadow, this was his "Sonic Heroes" reappearance.
It was the 4kids cast own decision to not return. Jason Griffith could have easily continued to voice Sonic and Shadow, but he decided not to.
Most people don't care for Rouge's censorship.
Amy being obsessed with Tarot cards is a element that was half-assed reintroduced into the canon because Sega doesn't know what to do with the character anymore.
Knuckles was never intelligent. He's been a bumbling idiot since his first appearance.
Eggman being a dad doesn't make him stop being evil
Frontiers did not save the franchise. The movies did.