I think you need to make a few exceptions though. It's obviously important for values-driven organisations to have the divestment option open. Why should a cancer charity have investments in tobacco firms for example. Equally at some point if your concerns about a given company are that strong it seems bizarre to keep engaging. But for most pension funds most of the time divestment is a dead end.
However I had a bit of a chuckle about the last line in the P&I article. Only Americans can write this sort of thing with a straight face surely?
Divest and the terrorists win.