They used to gripe about the excess cables under computer room floors and above T bar ceilings is always a nightmare.

I am not sure I have ever heard anyone say anything about cables in walls and the answer was always to simply label them "future use/spare".
The problem is that most old wire is not suitable for modern communications.
It does get down to the fact that only sloppy wiring can be pulled out without damaging the building finish. If it was diligently strapped, it is not coming out.

Greg Fretwell