"The idea that writing should be clear, concise, and low-jargon isn’t a new one—and it isn’t limited to government agencies, of course. The problem of needlessly complex writing—sometimes referred to as an 'opaque writing style'—has been explored in fields ranging from law to science. Yet in academia, unwieldy writing has become something of a protected tradition."
That's pretty much the thesis of the article. Anyway, I've certainly encountered academic writing with "tortuous syntax and sentences mostly devoid of meaning," although it's a small minority of writing in my experience. This article seems to suggests it's a conspiracy to keep the public out while signaling some kind of in-group membership. But I've always let Occam's razor guide me: a much simpler explanation is that many people (and academics are by no means free from this) are not good writers.