Why would knowing about them pirating Archer's ship even be useful?
In season 1 TNG when they were "the bad guys." Sure it would be obscure tidbit, but once they had a visual record to the name, someone like Data who memorizes things like that as part of his programming should've drawn the connection and corrected Picard when he called his encounter Starfleet's first contact with the Ferengi.
Which brings me back to either bad writing from Enterprise or incomptence from Archer. Take your pick. :P