When I learned to play electric guitar, I learned movable blues (pentatonic) box patterns/scales way before I learned anything (maybe even my first chord!).
We use them on mandolin, even though we probably don't know them as "box" patterns/scales.
The purpose of the box pattern is for the musician to get around on the fretboard and transpose from key to key easily. It also allows you to move your licks anywhere on the fretboard. It's all a matter of knowing where your root or "pivot" note is.
When someone tells me to play in a key I normally don't play in (say Ab), I can fake my way through by knowing what box patterns I can use for that scale and what's appropriate to the tune. I'm not the greatest musician ever (not by a long shot), but I'm rarely intimidated to sit in with someone. I can usually get around a bit. These box patterns are part of it. And even though I know all my major and minor scales, this is much more familiar to me and is great fodder for lick creation.