I think there's more to that as well. There are relatively few teams who have unprotected 1sts in 2014, 2015, or 2016 they could send. Of those teams, there are even fewer who have 1sts that would be worth sending for Rondo. Of those teams, even fewer who need a top-end 28 year old point guard (as many are in prolonged rebuilds or already have a decent quality pg signed long-term or on rookie contract).
EDIT: And on top of that, Sam Smith isn't the most plugged in guy in the world.