I get your point, and it doesn't blow my mind. The problem comes because you are doing an analysis from a perspective that is only technical. That is, at the "code" level you can have a game labeled NSFW that is not for adults.
But as humans, if we're looking for NSFW content, it's because we're looking for adult content.
You can argue that there are exceptions, the problem is that no matter what system you create, there will always be exceptions. Therefore, you must seek a balance between what you want to achieve and the resources.