The pass source code you linked to is just a wrapper for the unix toolset (and has twice the byte count, not that it matters). Pass has a completely different crypto implementation and security model than SpicyPass. The two are not synonymous, either in features or UX. I elaborated on more of the differences between the two in a different reply to a similar comment.

tl;dr different strokes for different folks. I didn't write spicypass with the intent of replacing pass.