I said this before and will continue to repeat it...People have a different opinion of what NSFW is . As long as there is no nudity involved (obvious one) that is SFW , but that is my opinion only.
Dont get me wrong , i agree there needs to be a way to protect underage people.
I actually don't get this, personally. I've never seen any convincing evidence that exposure to nudity or sexual imagery does lasting harm to children.