it is weird that Sonic's reputation never recovered from Sonic '06, a nearly 20-year-old game. they rushed it out about a year too early and ended up with lasting repercussions way beyond that
they could recover from it some day but- here's the thing..... since '06, which was followed pretty swiftly by Sonic Unleashed (2008), sonic has been putting out some pretty okay, not revolutionary, but okay, material. but the shadow of Sonic '06 is always looming over it. "The Sonic Cycle", and "will this be sonic's return to form?" etc.
without '06, you feel that they could have cruised by as a bit of a nostalgic product where the biggest lows of the series were things like "shadow the hedgehog" and other corny spin-offs