whats the point of having /r/frozenporn if its not going to be used?

Just because content could be posted to one sub doesn't mean it can't or shouldn't be posted to other subs. The existence of /r/elsamasterrace and /r/QueenElsa do not imply that there shouldn't be Elsa content on /r/Frozen because "what's the point of having those Elsa subs if all the Elsa content gets posted to /r/Frozen?".

I'll just copy and paste what kernco said when the /r/Frozen community decided against making a rule against NSFW content.

If there is one group that wants to see NSFW content, and another group that doesn't, this is the correct solution. Because if NSFW are banned, then those that want to share and discuss NSFW content simply can't. They are forced into the other group, essentially. But if NSFW is allowed but clearly marked, the SFW group isn't being forced into the NSFW group. They can choose to not click on things that are NSFW, and then they only see a SFW /r/frozen. One of these solutions is clearly the more accepting and compromising one.

The title of this post gave enough information for anyone who doesn't want to see this type of content to not view it. It's the user's responsibility to avoid such content if they don't want to see it.