That one point really gave me pause as well. As I posted the other day:
-----
"If your bottom-line is dependent on code, you know the angst of asking a programmer, “How long will {{ insert feature }} take?” You know programmers can jargon-speak their way to your consent and when everything comes crashing down, you are to blame. NoFlo frees your businesses from a labyrinth of text files so you can get-a-grip on what-the-hell-is-going-on!"
If you tell people that NoFlo is the solution to prevent programmers from "jargon-speaking" their way to your doom then... Sorry, that's just a lie with a topping of polarization.
The way to prevent programmers messing up your business is to not hire shit programmers and manage good programmers properly. Not hiring the programmers with the fanciest visualization.
But most of the proposed use cases are clearly bullshit, and using these languages/programs makes it clear why: organizing code in a single dimension is already hard... organizing it properly and sensibly in two dimensions much more so, as well as a number of other issues with order and tracking race conditions. For anyone who wants to really evaluate this technology, I would give these products a try.
Really though, functional programming and OOP both have sufficient support for data flows that it isn't really an issue for programmers.
But on serious note, with all the brains we have, we should've created some tools to automate things, progress is too slow. I think we can do way more.
After staggering expenditures of effort by some of the world's sharpest minds over more than half a century, I doubt there are any more major breakthroughs awaiting us in the field of programming languages. (Unless AI starts to play a major role, in which case I couldn't predict how programming would change.)
Most developer software is abstractions and tools to automate things. Tasks that were hard in 1995 are trivial today; most web developers have probably never had to think about the vast majority of things that web developers in 1995 concerned themselves with, because our libraries and frameworks and tools take care of them.
The complexity of the trade is ever-increasing, though, and so we need new tools and new libraries and new frameworks to deal with that increasing complexity. This is the biggest place where visual programming falls apart - it's fine at dealing with programming as it existed when it was released, but programming is not a static discipline, and evolves wildly and rapidly. Non-sentient tools just simply can't keep up.
LightTable is tool that one guy started as a futuristic tool, yet it is what we had before.
Complexity of our work is ever increasing and fun definitely never stops, I wish tools were better so we can enjoy languages more. As tools augment our ability to do work, having excellent tools would allow you to do more and be easier.
When you can't perform static analysis (which is very difficult to do effectively in dynamically-typed languages), many of those tools you are talking about are just not possible.