Because Sonic's plotline is that deep, right?
Who says that Wii and DS stories are going to be the same, anyway? Just because the game title is the same doesn't mean the dialogue is going to be identical. If they're different scenarios merely with thematic "wisp gameplay" similarities, then no explanation is necessary.
Some explanation would have to be given to why Blaze is in the game all of a sudden. And it would really serve no purpose whatsoever. Just let the game be without nitpicking on the absence of a single character who isn't prevalent in the Sonic series and is only wanted in this game because it's unofficially Sonic Rush 3.
It's not refreshing for Wii owners; Sonic-only is *ALL* they've done on that console, save for Black Knight.
And mind you, this "improvement" they're on has yet to be tested. Yeah, I'm hopeful too, but hope is what sustains this end of the Sonic Cycle. Further, I found Black Knight to be a significant improvement, particularly in its late-game (which is unusual for me since I tend to enjoy the early stages in other Sonic games), but unfortunately the public perception of hedgehogs with swords is a lot worse than hedgehogs with cyber-elves.
The Wii isn't the only console around, and Sonic Team has proved time and time again to not be able to hold the responsibility to handle more than one single gameplay mode without [tornado fang]ing it all up for almost ten years. So far, what we've seen of both new home console games they're making, suggests that they're at least decent and not a complete shitty mess like the ones before. We still have to judge that for ourselves, but for now, the system seems to be working. Aside from your favoritism for a game most people seem to hate and alot of other questionable choices, surely you can find this easy to understand? The one thing people need, is a GOOD Sonic game. At this point, as long as they can deliver quality to us, I will not give a flying [tornado fang] about whether the game stars Rocky the Raccoon or Honky the Hippo. Sega's keeping it as simple as they can in both of these games, while still offering simple extras to make it memorable. With everyone bitching about this "back to origins" bullshit, we need simplicity more than ever. We need a game that gamers, fans and reviewers can enjoy equally, a game which has the potencial to be fun for pretty much everyone. For now, from what we've seen, this seems to be travelling in that direction. It's an improvement on everything the halfway good parts of Unleashed were, built on the easiest home console to program for nowadays, on a system Sonic Team has experience with. Everything about this makes sense.
Anyway, Sonic fans will [sonic slicer] beyond racionality.