Because I haven't (to my recollection) gotten Tom's explicit approval to do so.
The Titans didn't become an accepted way to resolve issues between players until well after the OOC ban option was added. It is important to remember that Back In The Day, rulers were pretty much supposed to police their own realms for things like multicheaters and bug exploiters. The OOC ban was, at the time, a useful and important tool for that...but the Titans are way, way better.
Ok. That makes sense, it's just new to me.
I edited the wiki to make this clearer; feel free to correct to clarifiy further if it's needed.
http://wiki.battlemaster.org/wiki/Ban
