Boromir's search for Imladris

[Boromir88]

Originally Posted by The Mouth of Sauron

Another reason I still find it hard to believe that people in Gondor didn't know where Imladris was is this : People in Minas Tirith must have known of the existence of the Beornings, the Woodland Realm, Esgaroth and Dale - and they certainly knew where Rivendell was. Surely Denethor could have sent scouts into northern Wilderland to "ask around" ?

What I don't get is why you keep insisting the exact location of a hidden refuge (where even Aragorn has some difficulty finding) has to be common knowledge to every bloat in the story?