But it's silly crap like that that matters to advertisers. NSFW actually is the word "fuck", "asshole", etc. You might be able to say that at work, not everyone can without repercussion.
And that's not a stretch at all, it's why network television won't let you say either of those words either. Not next to their Ford and Samsung advertisements.
The entire premise of NSFW is silly to me. Like no one has an obligation to make sure YOU are safely browsing at work. Get back to work.