Cable routing, why not thru the back of the aerobar

Hi, I was wondering why the cheaper bars like the profile T1 or T2 don't route the cable out of the rear of the bars like the zipp vuka or higher end bars. I guess it depends on the frame so maybe thats why they drop out up in the bar. Has anyone done this themselves

I have to replace both my cables and housings because they are too short from a previous owner, so I thought, why not drill holes in the plastic plugs and route them out of the back then down into the frame like the more expensive bars.

I know, it might save me 1 second over 112, but I like a clean looking bike and I have to replace them anyways so why not?