It's perfectly normal. You do not have specified permission for it. Some people have permission to post tutorials here, the ones that are professional and capable of making them. If you want to help by writing tutorials, PM The Prototype with your tutorial attached and he will have a look at it, then he will decide if to, or not to give you the permission.
The list of people having permission;
The Prototype
The list of people having permission;
The Prototype