I see more ironic and comedic 40K material than I see actual 40K lore these days. Fuck I made a 40K lore joke post on here not to long ago and it was received well.
My point is, while there are actual fascists attracted to 40K lore, I think the phenomenon is overplayed more than a little. Fuck there are fascists in the My Little Pony fandom, fash dorks will latch onto anything. I think most 40K fans these days are fully aware it's tongue-and-cheek nature. I really don't think people who like painting goofy miniatures of armored dudes wielding chainsaw guns are any more predisposed to fascism than anyone else.
Meanwhile you try any of that shit in any of the places near me and you'd be thrown out instantly and would definitely not be allowed back. I think as it is with most things it depends on where you are and what kind of community the location builds.
And yes I have played 40k on tables in game shops full of people who were probably chuds, and they kept their damn mouths shut because they just wanted to play and knew they wouldn't be allowed to if they started talking about anything other than the game.
I'm all for chasing fash out of 40k, any My Little Pony, and the planet. I'm just saying I don't think there's anything inherent to 40k that makes it more attractive to fash than any other fandom. Fash are consumerist nerds, they'll glom onto anything. There are fash in the fucking Trek fandom for Christ sakes.