Why is a comment simply saying "contact me privately for further details" not allowed?

This comment does not provide any helpful information to other translators and undermines the point of the Blue Board. Translators are busy, if they went to a Blue Board record and every comment merely said "Contact me privately for further details." there would be no point in having the comment section at all. 

Site members can contact the translator who gave an entry for more details by clicking the "Email translator" icon on the entry itself.