So, on the topic of replacing cables - and prophylactically replacing rear shifter cables on STIs, there I'm in agreement with the OP. It has to be done, and why keep the old housings if you're replacing the cable? So, it's also bar tape (either discard or re-wrap), and the job gets bigger.
You have to keep more spare cables, more lined quality housing in more colors, more sets of bar wrap in various colors, etc. So the sustainment costs go up.
Of course, I love working on bikes, so this is like a day in the candy store for me...
Last edited by Phil_gretz; 03-05-20 at 12:22 PM.