I used to work for a business that sold into trading floors. The trading floors NEVER reused or removed old wire- they would just pull new runs anytime something changed. Its amazing how fast something like this gets created. ;-)
I wouldn't want to be that guy sticking his fingers in the water!
In the mid 90's I moved to south Florida to work for a large international firm and we had a large campus with many buildings, at least one if not more wiring closets on each floor of each building. Many of them look exactly like some of those pictures.
We had one, H2 it was called, that had so many cross-connect wires going between two sets of racks, that you walked on them - they completely covered the floor. It was almost like walking on snakes...
I used to do IT consulting for large company's and I have seen my share of wiring nightmares even removed a few and started over.
The worst wiring mess I had ever seen was before I started with computers, I used to do electro mechanical wiring and repair. And I once was called to a company to repair an old machine no one knew anything about. This huge machine was controlled by hundreds of relays, and the 220V electrical looked just like the 2nd pic with black wires. The worst part is people had been walking on all the wires that had been 10 inches thick above the floor routinely.