Totally makes sense from your standpoint, but not theirs, because again, they need a draw, and recognizable names like Justin Long are going to bring people to the theaters over an unknown name like Ross Bagdasarian. This is also why they brought in Jason Lee to play Dave: his career was really booming at that point, what with MY NAME IS EARL and stuff . . . even though not only was he horribly miscast, you can tell he isn't even enjoying making those movies anyway.