It allows you to install full length sealed cabling or hydro hoses. Although, a full rear brake cable will be more compressible so you will need to use a good quality housing. I used both Gore and Jagwire, even run a full cable on a Big Dummy and had no problems. Yeah, the zip ties don't look too good though.
Although, I much prefer a solution where you have braze-ons that are oversized for hoses or full housing but have shims for using regular cable stops if one prefers.