But that's what's the beauty of Steemit. Unlike other social media, it does not censor. That's what's the beauty of it and which will allow it to grow.
On the other hand, we as a community can decide whether we want such kind of posts or not. In this case, if you do not like NSFW posts, you can simply ignore it and thus when users realize that such posts are not accepted and not rewarded, it will slowly fade out of existence.
I talk about Steemit in my post : https://steemit.com/steemit/@stanthesteemer/why-steemit-is-the-future-of-social-media
Do check it out.