it's because he points it out every time and he does it constantly
It probably only seems that way to you because you thought it was edgy the first few times and then people made it into a short lived meme and even though that was long ago, your brain now goes out of it's way to notice each and every time he posts a picture of himself with a gun, and keeping that in mind only makes it seem like he's "constantly" doing it
And maybe there's some kind of paranoia going on here that makes people immediately assume that he's doing it for attention no matter how much he denies it, therefor starting a very unnecessary argument over what is essentially nothing