> I think XKCD's "up-goer five" is a suitable counter argument against words that are too simple to clearly communicate complex ideas succinctly. Jargon has its place in language.

Are you saying up-goer five is a good example of simple word usage or a bad example?

Anyway, parent poster is talking about how we should add rare and hard-to-understand words to make reading a more mentally challenging exercise as opposed to using words that describes the subject matter clearly and concisely, using the simplest words and phrasings that can adequately convey your message.

Your "extreme example" is abused by thousands and thousands of academics as an excuse for poor, hard to read and hard to understand academic writing. You can in fact write clear and concisely in a phd thesis. But since the author assumes the reader has a large background knowledge in the field, it will still not be accessible to the average reader.