I think that's part of it. I also think that NOT letting other teams know about who you want helps keep that player's price lower since there would seemingly be less competition for him, because other teams wouldn't say "hey, he's visiting Buffalo and they have the same needs as us, let's bring him in." Frankly I like it better this way, rather than hearing about everyone being paraded through, wondering whether he's worth signing, and then pissing and moaning because he didn't sign, or signed for too much.