Opinions do differ and it's not universal but it's certainly most common now. Especially since FD's went away and we got stealth routed droppers. (Which are also "solutions in search of a problem" right?) Definitely easier to fuss with the controls on a bike with external routing. Although with FD's gone with their six different adjustments there's a lot less fussing to do. Definitely easier to use a bike with internal routing. External cables and hoses are not protected and they and their stops are always in the way of something, a frame bag or the tie down straps on a tailgate pad or your shoulder.