[X] Boxes and arrows

[ ] Spreadsheet-like

[ ] Control flow block primitives

[ ] Grid world simulation

approach to visual programming. Your approach won't work because it gets poor scores in the following cognitive dimensions (https://en.wikipedia.org/wiki/Cognitive_dimensions_of_notati...):

[ ] Abstraction gradient

[x] Closeness of mapping

[ ] Consistency

[x] Terseness

[x] Error-proneness

[x] Hard mental operations

[ ] Hidden dependencies

[ ] Juxtaposability

[x] Premature commitment

[ ] Progressive evaluation

[x] Role-expressiveness

[ ] Secondary notation and escape from formalism

[x] Viscosity

[ ] Visibility

and the following philosophical objections may also apply:

[ ] Any schema based on undeclared program state is unacceptable

[x] Complex dependencies will get intermingled and make a mess

[ ] You can't have more than 50 visual primitives on the screen at the same time

[x] Function application is the wrong abstraction for flow graphs

[x] Similar proposals have been tried in the past, and failed

[x] It requires seeing the whole thing at once

[ ] It doesn't allow for in-place comments

[x] Evaluating program state is hard

Furthermore, this is what I think about your solution:

[x] Sorry dude, but I don't think it would work.

[ ] This is a stupid idea, and you're a stupid person for suggesting it.

[ ] Nice try, assh0le! I'm going to find out where you live and burn your house down!