I disagree also. It would have made for a hell of a lot better story for a comeback then 'ARGH, IM GONNA BEAT KANE AND SHOW YOU ALL IM NOT HURT ANYMORE'. Even if it has been done before.
Hell..they could even still use it sometime down the line, have some character..maybe someone in Evo talk to Edge, and say they have a 'special tape' show him..it's Edge getting attacked...and by who? None other then...CHRIS BENOIT!? (Who was his tag partner for that match..there's a plot twist .) That's probaly a better way to start a Edge/Benoit feud, as well as getting Edge into Evolution then probaly what's going to happen. And in this case Benoit wouldn't have to resort to heat.
Of course the fine line between face and heel would be...not so fine here, but so what. If they couldn't tell from the SS reaction, many are now pass staying in that whole 'face/heel boundary'.
EDIT- for those maybe saying why the hell would Benoit just up and attack Edge..well umm..as we all know Edge at the time was on the rise. About to get a title shot in fact, they could just go the Chris Benoit was gonna make sure that didn't happen route. So he took Edge out, solidifying his spot in the main event. (even though it didn't work out.) Of course..this may make him a tweener, or maybe a bigger face seeing as how people hate Edge..lol..but if it did make him a tweener, with people booing because of the backstage attack..IMO that'd be better, since I'm getting tired of 'smiling because I beat you Chris Benoit' And I want 'The Ice Man' Chris Benoit back.