I think people misunderstand what's happening. The people who are voting for J&E are generally not people who would normally pick up the phone and vote, people like me. Just because it's all good fun to me/them. So, if they didn't exist... these people would have been going out eventually, in the order that they have been.
If they win, hurrah! This competition isn't a show for talented artists... or else they wouldn't need the X factor. Surely we can all agree that there's nobody amazing this year and I, personally, could not stand another Leona Lewis/Alexandra Burke winning. Nobody different ever wins, it's always the same crap. And so, if John and Edward go on to be famous as a result I'd much prefer that than have to listen to yet more generic soulless crap on the radio.