Actually, the real reason is None of the Above, IMHO. Magazines write feature articles on guns made by companies that spend lots of money advertising in the magazine, that's the bottom line.
Most of a magazine's revenue, the overwhelming majority, comes from ad dollars, not subscription revenue or newstand sales. The way a mag approaches a potential advertiser is to tell them that if they place an adequate number of ads, they will get a feature article, or so many per year, depending on the ad amounts. It's a pure quid pro quo, it's not disguised at all if you're on the other side of the counter.
Been there, done that, personally, used to spend $4-5,000 per month on magazine advertising. What surprised me was the first time I got a featured article on one of my products and all the reviewer asked for was some good pix, he didn't actually want the product, it was too much work to fool with it.
Now you see why I don't read any of them, the internet has made magazines irrelevant.