Actually not really sure where this was reported that your saying you complained for a year. I did a quick check of your previous posts here.
Now however I just did a quick test. By default permissions are all on in a category setup until you set them. Now say I go in and edit Main say here on my clean install
Main Index - Omegatron.net Reviews
I uncheck banned and unregistered to not be able to post and click dochildren and if I go back and check my children of that specific Main cat it applies permissions to its specific children.