Reeving sheet for self-tacking jib

[Auspicious]

A friend recently took delivery on a Hanse 400e with a self-tacking 100% jib. The jib sheet has a 3:1 purchase to a car on a curved track. From the car the sheet goes nearly straight up to a sheave about 1/3 up the mast then down the mast to a turning block and line organizers back to the cockpit.

Question: why is the sheet routed so high up the mast? Why not directly back from the car? Is it entirely due to maintaining a fair lead regardless of the position of the car on the track?