I have used LabVIEW, among other visual languages, and built systems with 1,000+ VIs, which are the fundamental building blocks of code organization, and hundreds of classes. LabVIEW has VIs, clusters, classes, libraries, and projects, all of which are useful and required for a well-managed, decoupled code system.
With good software principles, there's nothing that says you can't organize and scale visual code well.
I one time interviewed at a place that had swore off LabVIEW and were moving to Python. The reasons of switching from LabVIEW were the same tired reasons of organizational issues. When I asked to see their Python code, they showed me a single Python file over 10,000 lines long, and there were function signatures that were over 20 lines long. That was just the function signatures. This example, along with many more, and my experience in both visual languages and text-based languages make me very skeptical about claims about not being able to organize and scale code in visual languages.
