Technically, the runtime is the easy part (relatively speaking). Modelling an array of swimlanes on a plain-text 2D page is the real challenge here IMO.
But a visual language either requires specialist tooling which I think deters a large number of people, or if implemented in plain text, degenerates into ASCII art, which is very hard to manipulate in a simple text editor (believe me, I've tried!)
A structured non-visual language is also possible, but that turns fairly quickly into a functional language which per se is not bad, but is not helpful when trying to present the overall flow of data around the network. You still have to jump around the file from function to function to try and understand what is going on.
There must be a middle ground out there somewhere. Simple plain text presentation of multiple streams of processing.