That is a good point. Basso will always be more attractive to potential teams than JU because (1) he is considerably younger, (2) he has done better in recent GTs, and (3) he has less questions about his motivation/condition in certain parts of the year.
That being said, Basso had particular appeal to the US team DC because an Italian is probably more palatable as a team leader than a German (that's sad and it shouldn't be that way, but it probably is).
Therefore, in a way, Basso's finding a team may be good for JU because other teams (e.g., Baroloworld) will know that they will not get Basso and will think more seriously about JU.
Here's an analogy. Let's say Manning didn't have his long-term contract, and neither does Brady. If Manning and Brady are both out in the free agency market in the NFL, even for the weaker of the two (one can debate this), it probably is better for the stronger one to have signed with a team and to announce it. Then the remaining teams looking for quarterbacks can recruit the weaker one more agressively. A real life example may be Adam Vinatieri and Jeff Vandewhatever. Let's say everybody wants Vinatieri more than Jeff. Well, Adam's signing with the Colts (given that the Colts didn't want Jeff anyhow) was good for Jeff, because it meant that other teams looking for kickers wouldn't be holding out hopes for Adam any more.