Yes, I'd like to see more on this from Bill.
On a more general note:
Writers leave agents sometimes--if four writers have left an agent, that doesn't necessarily mean that there's anything wrong with the agent (or with the writers, for that matter). Sometimes writers find an agent who's just a better match; sometimes agents decide to focus on certain literary genres and markets and scale back on others...there are so many reasons that an agent/writer relationship can come to an end, and only a few of them reflect poorly on either party.
This is not a comment on the Malaga Baldi Agency, because I don't know anything about the agency or its relationships with its former clients. Just saying that certain writers have left the agency doesn't really tell us anything about it, though.