Ugh, I hate that mentality. You can be plenty tight with a full lineup that properly rehearses, performs and practices their craft. You don't need to have all your harmonies in a row and every pizzicatto "plink" lined up to the 32nd-note kicks to be a convincing live band. There are exceptions of course, I couldn't imagine listening to a Rhapsody gig without the symphonic layering but bands like Into Eternity running all their guitar effects and clean/dirty channel switches through a protools session leaves me cold. Makes your gig look/sound/feel about as canned as your backing tracks.