I see you comparing the numbers but I don't think it's all about that in getting your request approved, you had just 18 active members last month while we had over 70, all engaging in production discussion as we mandated on the thread with low quality been deleted (discouraged). Lets talk about the activeness of our local users on the general forum, you can take a look at the names on the table, alot of them are quite productive on the general forum and Nigeria like thread are filled all over the forum.
This is an aspect that affects many local boards. There are many users who, despite being from a particular country or language, end up not participating in that country/language board. Perhaps because of the aspect you mentioned, because they think it has greater privacy or repales.
I think this shouldn't happen on a forum like Bitcointalk, although unfortunately I know it happens.
In turn, I don't think it's the fact that it only has 18 active users, clearly, that prevents them from having a local board. Those 18 can be much more active than the 70 of other cadres (I'm not saying that those 70 participate little).