Would it be possible to enable the "Enable smiley set selection by members" setting?
This appears to be the only way Simple Machines permits a member to set graphical smileys = Off. I have to keep going back and edit posts to tick the Don't use smileys checkbox that's only available on a per-post basis via Attachments and other options, to rid my posts of those wretched graphical ones. (You can't change this setting with the inline reply box.)