Remember that insanely arrogant and anti-intellectual screed about how "enthusiasm is indistinguishable from academic rigor"? For all their rhetorical posturing (of which @carriesthewind did a fantastic analysis), that writer clearly doesn't know what "academic rigor" actually means. It's not just that they're wrong, it's that they're wrong in a way that perfectly demonstrates exactly how wrong they are.
So, Ariaste seems to think that "academic rigor" is about YOUR passion, YOUR enthusiasm, YOUR hyperfixation, YOU YOU YOU, it's all YOU AND YOUR FEELINGS. But the baseline for calling something "academic" is that it passes peer review. All publishing (fiction or nonfiction) goes through editors, but academic publishing has one necessary extra step: it gets sent out to other experts in the field, who evaluate whether the work is following the right disciplinary protocols, is using evidence reasonably and responsibly, and is meeting the professional standards of that field. Academic work is a very specific conversation, and if you want to participate, you have to prove--and keep proving--to other experts that your work is up to snuff. That's because academic texts are speaking with a particular weight and authority, which is a serious responsibility. Peer review is quality control.
You can't practice as a master electrician or a lawyer or a rabbi unless you've fulfilled the requirements specific to those jobs, as determined by credentialed experts in those fields. It is simply not your call: "academic rigor" is something academics get to define, because it is our term for our professional standards. Unlike Ariaste's self-centered FEELINGS, real academic rigor is a collaborative process that requires formal input from other experts.
So, some people on my dash are reading John Green's book Everything is Tuberculosis, and are enjoying it and learning a lot; all the reviews I've seen, including from professional epidemiologists, are very positive. But no one--including Green--is using the term "academic rigor," because this book is not being presented as an academic work! It is, by all accounts, very well-researched, thoughtful, and conscientious, and an excellent and accessible discussion for a general audience. Green doesn't need to meet academic protocols, because he's not writing for academics. That is not the conversation he is having, and it is unfair to apply that model of evaluation. Explaining specialized material to a wide audience is important and necessary work, and creative writers and journalists often excel at it; many academics... do not. They're different skill sets, that follow different rules, for different conversations. Correct labeling is what matters here.
You can't call an Italian sparkling wine "champagne," and you can't claim "enthusiasm" is the same as "academic rigor." They are different things. Champagne, like academic work, must adhere to particular standards in order to get that label. To someone who knows nothing about wine, champagne and prosecco might seem identical. They might be equally delicious, and can be appreciated as such! But taste is subjective; "this wine is/is not from the Champagne region" or "this did/did not go through peer review" is not subjective. And anyone selling Italian wine as "champagne," or saying "my PASSION is equivalent to professional expertise," is making a fraudulent claim. They are mislabeling their work to claim an authority to which they are not entitled. It might be out of ignorance, not a malicious attempt to deceive, but the effect is the same.
Now, in my field (folklore), we place a high value on "tradition (or culture) bearers": people from a folk community with a great deal of specialized knowledge of that community, like, say, a longtime participant in a fandom. This "vernacular knowledge" is specifically sought out and respected within folkloristics--we literally cannot do our jobs without it! But when I publish an academic piece, my work will have to be sent out for review by other folklorists, to make sure that it is engaging appropriately with the discipline. If I want my work to be taken as a serious entry into that conversation, I have to follow that set of rules.
Succeeding under that rule set is extremely difficult without high-level training. It's not impossible to acquire knowledge, especially if you have access to a university library, but engaging with that knowledge on par with our professional norms requires a lot of guidance from people in the field. And the best way to get that is through a formal graduate program. Of course, access to those programs is limited in all kinds of unfair socioeconomic ways, and there are lots of passionate, talented people who would make great scholars, but never had the opportunity, which sucks. But that is a different conversation.
It's uh, interesting, that so many people who spout this line are whining about humanities academia. Like, I'd imagine that even Ariaste understands that a "passion for medicine" doesn't entitle you to perform heart surgery. Reading lots of books is necessary for professional expertise, but it is not the only thing: you need immersion in the community of other experts, to agree to a specific and enforceable set of standards, and to have your work formally approved, to claim that level of authority. Not seeing literature or history or folklore as deserving that level of professional analysis sure says... something about how much you value them.