The things that make us cringe
There are many things in this 40k that just make people as a fan cringe. It could be something like Draigo who is so OP, or it could be something that is so minor it only bothers you.
Write down the things that make you wish they never existed.
No engineering degrees: There is an entire cult devoted to machines and science, they can make some cool tanks, weapons, machines, but dreadnought armor forget it! there skitarii can even wear something that is "like" terminator armor, but isn't. This right here bothers me so much, I just pretend it doesn't exist in the 40k world.
bolters design: It's too outdated looking, I'd prefer it to be bigger and look a little more hefty, it looks like an mp5 in size comparison on a Space Marine. Also it needs a stock. You shoot a rifle without a stock and tell me how accurate you are.
1000 men strong: The size of a chapter never bothered me before, but a post on here talked about how another 0 should be added to make it 10,000 marines, and the old legions should have had 800,000+ marines. It made so much sense, and I cringe a little bit every time I hear about only 1000 marines. That's really not a big number at all, and even 10,000 in the grand scheme of things isn't big either.