I always appreciate it when people mention their misgivings about stuff because that makes me go over the concept again myself.

In this case it popped up with a case that would have to be taken into consideration when programming. For entries that were marked 18+, the internal age-check could not be bypassed with logged-in users (though the <18-year-olds should be able to use a URL argument to bypass a NSFW splash page if they want to).