I agree with you how-ever the elephant in the room is a image or topology doesn't predicate anything (A predicate is seen as a property that a subject has or is characterized by). That is the main delineation between them, and why SPO (subject predicate object) is used universality by all modern languages - abet some have different svo ordering but I digress.
The next major draw-back with visual programming is they don't explicitly convey time. You have to infer it via lines or sequence of diagram blocks. Were in a programming language you have sequential order of execution eg. left to right, top to down of of the program flow and stage change. If you attempt to achieve the same with a stateless event driven bus or message queue, you end up having to embed the sequential control flow into the event payload itself.
The next major draw-back with visual programming is they don't explicitly convey time. You have to infer it via lines or sequence of diagram blocks. Were in a programming language you have sequential order of execution eg. left to right, top to down of of the program flow and stage change. If you attempt to achieve the same with a stateless event driven bus or message queue, you end up having to embed the sequential control flow into the event payload itself.