> because as much as people yell, NSFW makes up barely any of the front page content
This is a really important point. From what I can see, Imgur doesn't have a porn community, it just has a lot of porn because it's used as an image host by outside communities. Porn is probably a net drain on profit for them, since they make their revenue off of people who use Imgur itself, not from servicing direct image links posted on Reddit.