When I looked at this, my immediate reaction was how awful long the files are. A programming language's community should encourage smaller files that do one thing.
i like large files, it makes it so much easier to read the code, figure out what it does, find stuff, and refactor. i like it when the entire program is just one file, except for the modules source. i hate when there are 10000 files all containing 5-10 imports and then just one or two lines of logic. or worse; include files within include files several levels deep that all touch global variables. my idea of good abstractions is to only lift out code that has no couplings and no shared logic with the program, like modules that can be reused by other people in other programs.
The files are long on purpose -- as the article says: The code samples where chosen by finding popular repos for each language and using the longest file in each repository.
One of the examples is the jQuery source code, but the long file shown isn't the actual source. The real source code is broken up into a number of much smaller files, and the jquery-2.2.4.js file shown on the page is built from these smaller files.
