Not really — perhaps for navigation or simplistic formatting. (Both of those are not strictly-speaking "reading".)
However, for writing computer code, text is fine (as long as you have a decent editor). From time to time, someone comes along with an idea for a graphical programming language, where you create algorithms visually, but these never seem to amount to anything.
I think you misunderstand: I'm not saying that the language should be atextual, but that text is unsuitable for storing programs.
As I said before: there is no way to guarantee a textfile is a valid program; on the other hand, a structured data-format can.
To be sure, there are fancy IDEs, such as Xcode, which are geared to producing GUI apps. These can help out by generating boiler-plate code, maintaining the project build script, and doing certain refactorings. But, ultimately, you are still left dealing with textual source code, be it Objective C, Java, C#, whatever.
Yes — and there's a major failing in that they view programs as text.
Text is also quite robust for data storage and transmission, e.g., CSV, XML, YAML, JSON. However, binary formats will outperform text, at the cost of some increase in fragility.
Right.
What I meant to say was that even basic HTML markup improves the readability of text.
E.g., in your #11, you used <ol>, <tt>, <i>, <sup>. These and other simple elements of HTML markup made your post easier to read than it would have been, had you been restricted to writing pure tty-compatible ASCII.