Well said. This is also something that I don't buy from the criticism towards Lisp. Something along the lines of: "Lisp did not become mainstream because everyone writes their own little language for their project, and so no one can understand other project's code."

pg wrote excellent arguments against this criticism in "On Lisp" § 4.8 Density, which apply just as well to the discussion above:

    “If your code uses a lot of new utilities, some readers may complain that it is hard to understand. People who are not yet very fluent in Lisp will only be used to reading raw Lisp. In fact, they may not be used to the idea of an extensible language at all. When they look at a program which depends heavily on utilities, it may seem to them that the author has, out of pure eccentricity, decided to write the program in some sort of private language.

    [...]

    If people complain that using utilities makes your code hard to read, they probably don’t realize what the code would look like if you hadn’t used them. Bottom-up programming makes what would otherwise be a large program look like a small, simple one. This can give the impression that the program doesn’t do much, and should therefore be easy to read. When inexperienced readers look closer and find that this isn’t so, they react with dismay.”