This is an incredibly mild insult in common usage — on roughly the same level as "jerk," I figure. What word would you have used to convey the same idea? I can't think of a less offensive choice.
I agree that it's a mild insult in common usage but I don't consider A List Apart to be common. I consider it to be top-notch and on par with leading print publications. I feel like if I opened the any well-respected periodical I'd be off-put by a similar title. "Nissan Corp is a Douchebag". Sounds silly, doesn't it? It felt like it was a cop-out to be edgy for edgy's sake.