It must increase the chances of it snagging on something.
When it's routed via top tube and seat stay it always makes the final loop of cable outer look really long - actually it's probably no longer than if it were coming from a stop on the chainstay.
When it's routed via top tube and seat stay it always makes the final loop of cable outer look really long - actually it's probably no longer than if it were coming from a stop on the chainstay.