And yet it's not really even academics or SJWs, D&D has always been somewhat irksome to the left.
Firstly, you have non-governmental people armed and using arms to defend themselves. Okay, some people who insist on medieval authenticity in a fantasy game seem to have a problem with this, but I believe in some D&D settings, some places have "sword control"
Secondly, there have always been complaints about alignment, about there being a concrete evil and good. Never mind that god, creatures, and planes of existence literally exist and are aligned with them.
Thirdly, constant bitching about paladins to the point where in the name of equality, every alignment got a paladin
Forthly, the whole orcs/drow being evil thing. Which actually strikes me as somewhat being at odds with leftisim, since they believe that "evil" is mostly societal and have no problems considering all white men/Christians/capitalists evil.
Moreover, there are quite a few tropes that do not sit well with the more conservative elements in society.
• The whole premise that a village peasant can become a high level fighter that commands troops and has domain over a large territory is based on an egalitarianism that runs against the whole class system mind set. Of course, social mobility does appeal to the vast majority of Americans, but being British I am more familiar with the right being the more "know your place" types.
•The principle of Noblesse Oblige is central to the fantasy tropes common in D&D and similar games. And it cuts both ways: This means that if the BlackEagle Baron is a douche, then the PCs, peasants or otherwise, are pefectly justified in usurping him and Bargle too. Oh and taking their stuff. Righ out of a Trotskyite revolutionary's handbook.
• Multiculturalism: most PCs in B/X and AD&D spoke more than one language and Halflings, Elves, Gnomes and Humans all live cheek-by-jowl in campaigns like Greyhawk and FR. Moreover, they interbreed! Miscegenation is a big no to many on the right.
• Loose Borders: in many adventures and campaigns that I have read, the PCs go wandering across nations and regions without a great deal of difficulty. Freedom of movement is kind of taken for granted. No talk of building big walls unless it is to keep White Walkers out.
Nearly all of these don't ring true to me on both sides.
Regarding alignment and armed adventurers - both of these are frequently complained about by people of all politics who prefer more realistic behaviors and society. If you look at the recent thread on adventurers wandering the city in armor, it wasn't politically divided. There are people who prefer their game morality to be more grays than black-and-white, and from my observation they are of various politics - maybe more libertarians and moderates, but not strongly so.
At present, the mainstream right wing doesn't have a problem with social mobility or miscegenation. If anything, it is a right-wing view that any peasant or lowly halfling can become a mighty lord if they just buckle down and work hard enough, instead of choosing to be weak and poor.
Of all of these, the two that have some substance are the drow/orc issue and PCs overthrowing authority. I have noticed that right-leaning GMs have buttons pressed more when PCs try to overthrow authority figures. And some left-leaning people have a problem about the portrayal of evil races.
On the other hand, these don't amount to all that much. For the most part, D&D these days is middle of the road politically. Publishing an academic paper that almost no one has read isn't comparable to Pat Pulling and B.A.D.D. in the 1980s. I live in the SF Bay Area - probably the most left-leaning area of the country, and no one bats an eye if I run a D&D game in my local group or at a convention.