Chris Moyles would be a more apt replacement for Simon Cowell than Louis Walsh because he has the ability to be a complete asshole. Louis would be better replaced by someone with a similar personality, like Michael McIntyre (but not him, for the love of god not him) - somebody who's all about camp humour. Maybe John Barrowman. There are just so many people who could do it better than Louis, but because the other judges all left in a mass exodus, he's now a vital part of the show. Utter farce.

Not that I'd want him to be replaced, but it'd need to be someone who has musical experience in some way. As if John, Michael or Chris have that...

I'm not saying they do, I'm just giving examples of people who fit the character profile.