I agree that it's not completely well-defined. It definitely seems like blocking all NSFW content would maybe block some content you would have wanted to see. This is just the price you'll have to pay for blocking NSFW content, and there's no easy way around that.
However, the comments on alexanova's post definitely made it seem like some people would be more than willing to pay this price. So at the very least, they could be given the choice and left to choose for themselves.