All I can say is, have you tried to use a CASE tool to do actual coding? I have, forced on me by various MIL-STD compliant projects.

X and Y both talk to A and B. Represent that in 2D without crossing lines.

Okay, you can, sure. If X and Y are at the top, and A and B are at the bottom, Twist A and Y, and the interconnection x in the middle goes away. But, you know, X is related to Y (same level in the sw stack), and I really wanted to represent them at the same level. Opps.

And, I'm sure you can see that all it takes is one additional complication, and you are at a point where you have crossed lines no matter what.

Textually there is no worry about layout, graphically, there is. I've seen engineers spend days and weeks just trying to get boxes lined up, moving things around endlessly as requirements change - you just spend an inordinate amount of time doing everything but engineering. You are drawing, and trying to make a pretty picture. And, that is not exactly wasted time. We all know people spend too much effort making PowerPoint 'pretty', and I am not talking about that. I mean that if the image is not readable then it is not usable, so you have to do protracted layout sessions.

Layout is NP-hard. Don't make me do layout to write code.

tl;dr version - code is multi-dimensional, but not in a 'layout' way. If you force me to do 2D layout you force me to work in an unnatural way that is unrelated to what I am actually trying to do. You haven't relaxed the problem by 1 dimension by introducing layout, but multiplied the constraints like crazy (that's a technical math term, I think!)

And then there is the information compression problem. Realistically how much can you display on a screen graphically. I argue far less than textually. I already do everything I can to maximize what I can see - scrolling involves a context switch I do not want to do. So, in {} languages I put the { on the same line as the expression "if(){" to save a line, and so on. Try a graphical UML display of a single class - you can generally only fit a few methods in, good luck with private data, and all bets are off if methods are more than 1-2 short words long. I love UML for a one time, high level view of an architecture, but for actually working in? Horrible, horrible, horrible. For example, I have a ton of tiny classes that do just 1 thing that get used everywhere. Do I represent that exactly once, and then everywhere else you have to remember that diagram? Do I copy it everywhere, and face editing hell if I change something? Do I have to reposition everything if I make a method name longer? Do I let the tool do the layout, and give me an unreadable mess? And so on. The bottom line is you comprehend better if you can see it all on one "page" - and graphical programming has always meant less information on that page. That's a net loss in my book. (This was very hand-wavey; I've conflated class diagrams with graphical programming for exmaple - we'd both have to have access to a whiteboard to really sketch out all of the various issues).

Views into 1D code is a different issue, which is what I think you are talking about with NoFlo (I've never seen it). If you can solve the layout problem you will be my hero, perhaps, so long as I can retain the textual representation that makes things like git, awk, sed, and so on so powerful. But I ask what is that going to buy me opposed to a typical IDE with solutions/projects/folders/files on a tab, a class browser in another tab, auto-complete and easy navigation (ctrl+right click to go to definition, and so on)? Can I 'grep' all occurrences of a word (I may want to grep comments, this is not strictly a code search)?

Hope this all doesn't come across as shooting you down or bickering, but I am passionate about this stuff, and I am guessing you are also. I've been promised the wonders of the next graphical revolution since the days of structured design, and to my way of thinking none of it has panned out. Not because of the resistance or stupidity of the unwashed masses, but because what we are doing does not inherently fit into 2D layout. There's a huge impedance mismatch between the two which I assert (without proof) will never be fixed. Prove me wrong! (I say that nicely, with a smile)

Sorry for the length; I didn't have time to make it shorter.