It has been done on purpose. If a none authorised member click on that button a custom message will appear explaining why he doesn't have access. I do it like this to avoid to waste my time explaining to some users who are not familiar with the administration permissions why it doesn't work. I could have included this line of code 'permsBbm' => XenForo_Visitor::getInstance()->hasAdminPermission('bbm_BbCodesAndButtons') in the view parameters of the template to let administrators modify the admin template with a simple conditional, but admin templates don't have child styles and will be then overriden each time an update will be made.
