Even though Scott Pilgrim was only the bassist in Sex Bob-omb, if Justin Bieber had played him, he could’ve been the lead singer. Besides, you’d never get noticed for playing base. Who does he think he is, Flea?
In the comic, SPOILER ALERT, Scott Pilgrim is 23 and he’s dating the 17 year old Knives Chau (this is before dating Ramona of course… hey, I said “spoiler alert”). This relationship would seem a lot more appropriate if both parties were teens, instead of the whole “of age” argument. But once he starts dating Ramona, well we’re back with the original problem.
Bieber has a lot of street cred, as he’s “owned” by Usher. Michael Cera has, well, NO street cred due to his association with Jason Bateman. Scott Pilgrim would thus seem a lot less geeky and a lot more gangster, thereby appealing to all teenage white boys living in suburbia who think they’re Eminem.
Who wants to see epic fights anyway? With Justin Bieber, he can have dance-offs against the 7 evil exes. Everybody loves dance movies, right? I mean, they made Step Up 3D, that’s gotta prove something.