That's some sales pitch. Vocal processors process. Yes, they can do some pitch correction but there is no "perform miracle" setting on them. If there was, there wouldn't be an American Idol show. Garbage-In-Garbage-Out does apply here.

I'll bet the next customer that came in couldn't play and the salesman said "don't worry, this is an arranger, the styles play for you." The next customer was a guitar player, "don't worry, we'll just turn up the distortion"