While in the abstract this is true, the physicality of the railroad representation more closely fits what the brain sitting at the computer evolved to comprehend. In other words, its a more intuitive vocabulary for the same language.
I too wondered that, but at least I didn't feel so. In fact a complex enough railroad diagram was worse for me. I particularly didn't like a backward railroad, often seen when the diagram would have been too wide unless wrapped, because it doesn't look different from other forward railroads...
