I find simple math to be much more elegant and easier to comprehend then a jumbled visual diagram. It's much easier to understand a universal quantification in a standard notation than reasoning by visual analogies.

Programming languages tend to be a little less expressive and elegant. They're more complicated too. For reasons of course... but I don't think I'm going to be writing algorithms and data-structures in such a tedious notation as a diagram.

Graphics are good for some things but programming I don't think is one of them.

Some things look best in text and it's fine. However, "programming" is a very broad category, and definitely does not boil down only to algorithms and data structures. I'd even say that most programming tasks in the world right now are much less about complex algorithms and much more about everyday systems plumbing. Sure, at some point you'll need to fire a complicated linear algebra kind of algorithm, but before you get there, you need to get the data out from some source, do some reformatting, decide which algorithms to run and when and then send the results somewhere else. And for that, seeing what is happening with your data the moment you try a solution, and deciding the next step based on immediate feedback is great.

This is pretty much why we've gone with interchangeable representations instead of going "visual only". The choice of the proper tools / representations highly depends on the context, and we want to leave that for the programmer's decision.

Are you familiar with category theory? I've been finding it very helpful for processing things visually. Considering this is "category oriented programming," I'm betting they find it helpful, too ;)

Actually diagram might be better suited, for example to display the difference between sequential in parallel tasks.