I'm not staff but I had a lot to do with the four day rule when it was initially made so how I see the issue: All forums have restrictions, some as many as 14 days with a post requirement (digitalpoint), this is the only effective way to stop spam. If we were to have moderators approve everyone they would have to go by some sort of guideline, most likely time registered or useful post count. This would be time consuming and present no significant advantage over automated approval.

The reason we use a post count only method is because members would often join and post ten pointless posts to get access, often ten consecutive threads in a single forum. This was very spammy and had to stop. We still get it from time to time with the occasional dumbass who didn't read the rules but it was almost completely cut.

In this particular instance, the member clearly had no intent of actually partaking in the forum. He wanted to make his thread and leave. He is one of the types the rule was designed to prevent from coming in.

edit: Dan's suggestion makes a lot of sense. Perhaps we could have that and allow anyone to post in it, but only four day members to see it (with the exception of members seeing their own thread).