I think that depends on the level of effort put in to create the tracks. If you use a $2.50 commercial karaoke version or just string together a bunch of canned loops in a sequencer then yes, I agree. But as the guy who puts ours together, I can tell you I appreciate things on a whole new level. Putting the right notes in the right order is, by a country mile, the easy bit. Getting things to sound well through the PA alongside all the live stuff is not, especially once you go beyond just drums/percussion. At least half of my tracks also have fully orchestrated strings or brass, some have a few layers of synth bass and some have additional vocal harmonies. Everything is mixed down and mastered to *.wav at rehearsal to ensure it all works once all the live stuff is added. I can tell you I spend more time on the backing tracks than on playing the bass...