Haha, remember the conversation about the dildo parties? Well I was still doing them when that book was first getting popular, and I'd get requests to do 50 Shades themed parties. They were always the most awkward ones because the women who supposedly were so interested in buying paddles and bondage tape had no clue how to actually implement them. I had one customer call me afterwards saying she didn't think it was actually supposed to hurt because otherwise why would anyone enjoy it.
I wouldn't call myself an active practitioner of BDSM, I've dabbled a bit but that's it, but I have friends in the community and people who think they want to be sexually edgy because of these books/movie but don't take the time to understand it are a pain (pun intended).
You're right, it's fiction. But so is Twilight and you have those kids who think they want to be vampires and don't take into account the safety issues there either. Probably shouldn't blame the authors but it's still annoying.