I mean ultimately, at that point in time, as far as describing the physical infrastructure of underground telecomm lines... its not an entirely innacurate description.
It leaves out the entire concept of software and DNS and everything about how websites and IP protocols and such actually work but uh... there at least actually are a series of tubes, lol.
I hate to defend it. But considering he was trying to present an analogy his peers could understand, I get it. You can build a bigger pipe, add more pipes, or push the water faster. It's not far off the mark in that respect to the analogy.
And you're right about exclusion of networking principles. You could build a very convoluted model of water distribution using networking rules.