A little googling and it seems like these brakes are designed to be tucked away behind the fork and behind the bb/chain stays. That might explain why the cable comes in from the side like that; I guess you couldn't route the cable to a typical road caliper when mounted in those positions?

Maybe Specialized spec'd them on this bike to get them hidden behind the front fork but then just decided to use a matched set instead of having a different brake on the rear even though it is positioned on the seat stay brake bridge and not down low.