I mean as far as metaphors go, it's really not that bad. It's visual and immediately understandable, and at least connected to the underlying thing it's describing (network traffic really does flow down a series of wries/cables that are functionally "tubes" of electrons or photons). Hell, people have been likening an internet connection to a "pipe" since at least the 90s (it was already a thing when I first got internet access in '95).

Sure the guy who said it was a dickbag, but I can think of a dozen worse analogies offhand.