I understand the standard belief is the Boras is scum, but the system begs for this to happen. MLB put in a place an informal structure in an attempt to limit the increase in bonuses. The only leverage draftees have is to take it to the final hours. The system just begs for this to happen every year. I belief the slot system has only been in the last couple of years (maybe three) and each year some big fish or another doesn't sign.
So it's really not only Boras, it's the system as it presently consists. As for never drafting a Boras client, I think it's more the matter of having trouble when you draft a high pick. I know we've got at least one Boras client on the roster, but I don't recall who it is (one we drafted, I believe - I'll check later and report it). But this would be a reason NOT to tank this season. Odds are the top player available is going to want Scott Boras negotiating for him.