Dude, nothing Sega can do can save the Sonic games. Half of the things I see you guys complaining about I hear complaints about the games for NOT doing. Sega knows that Sonic Fans are more like the Red Sox fans and will keep on coming back to the game only to be disappointed and swear off Sonic Games forever only to come back thinking "Hey they'll get it this time!". Sega can do anything and attach speed to it and the fans will buy it.
But of course when they come back to Sonic Adventure...the fans complain because it's not high-speed blast-processing. And when they just go back to holding right on the D-Pad and occasionally hitting the "a" button until the boss fight, other fans complain because that gets very old.
Everyone has so many different expectations for the game I would personally NOT know what the heck the fans want. Fans are JUST as responsible for killing the Sonic Franchise as Sega and Sonic Team are. (And I am of course leaving the stuff you see on FurAffinity out of this argument) If oyu ask me the only characters they should remove are Big and Cream. I like Amy - keep her. She can actually DEFEND herself, if Robotnik is gonna try to kidnap her and hold her for ransom, she'd smack him in the nose with her hammer and escape, whereas Cream would be all "OH SONIC TAILS HELP ME HELP ME!".
If you ask me if Sega cared at all about how their games were received and now how they sold, they should just make a new platforming game that no one has any expectations for. Just let Sonic go the way of Alex Kidd and Wonder Boy or just let him become a secondary franchise that people will recognize, unlike Space Channel 5 which isn't really known to anyone.
I seriously believe Sega just cares about how well it sells...look at Shadow the Hedgehog. I went into a Target recently and found that game labeled "Greatest Hits", of course right next to much more well-received games like Shadow of the Colossus. It's obvious that those are based off of sales - if I recall, Valkyrie Profile and SHadow Hearts: Covenant were VERY well received but you had to go to eBay to find them within years. (HEck I only saw Shadow Hearts: Covenant in stores until mid 2005)