The reason was that our class paper assignments were not about arguing philosophical points. Our assignments were to summarize the arguments of philosophers. No personal opinions. Just summaries.
Regardless of the substance of the course, the skill of digesting, analyzing, and summarizing the position of another is surprisingly valuable. It is also surprisingly difficult.
Summarizing is difficult because it is too easy to mix up personal ideas with those of others. This tends to result in a mish-mash of words and ideas that don't fit together, resulting in the incomprehensible academic-speak complained of in the article.
Summarizing is important because it is persuasive. If you can rephrase your opponents' views without bias or argument, and then build on those views to reach your conclusions, your opponents are much more likely to entertain and accept your conclusions, because they feel like their views have been fully heard.
It is unfortunate that so much of writing focuses on making arguments, to the detriment of the equally important skill of understanding the arguments of others.