> 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.

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

A bad example (because of the resulting verbosity and inexactness). It's an example of how simple words are inadequate to explain complex ideas succinctly

> You can in fact write clear and concisely in a phd thesis

You ignored the rest of my sentence. I did not say [you cannot write a "clear and understandable" PhD thesis]. I said [you cannot write a "clear and understandable" PhD thesis in Linguistics while avoiding five-dollar words]

> 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

Who exactly is the "average reader" of academic writing?

It sounds to me like you are making a blanket statement: "jargon is bad". I am saying jargon provides useful ways of expression.

There's a nice table with $5 and $.5 words here:

https://www.prismnet.com/~hcexres/style/pompous_words.html

First time encountering the expression for me. It's not about jargon, as far as I can tell.