Why not try to help them become a better manager instead of bashing people? Odds are that they're getting hammered by upper management for missing those dates and crap rolls down hill. I don't disagree that some people are just bad managers, but if you could give them a suggestion that helps them better communicate the message from you to upper management then I don't see why not try. The method I suggested just gets them to ask for an optimistic and pessimistic estimate in addition to the most likely date. Then they average the 3. So, you get to quantify your caveats... Unless the person really doesn't want to do anything other than griping about missing dates, then they should be open to it.
IDK Gordon, I suppose I tend to understand why management takes a certain position and then peel that onion back and see what their real interest is/was. A lot of times it makes my life a lot easier in the long-run to try and make them successful. I'm not trying to defend them since I clearly don't know all the details, but MS project or primavera are only as good as the data.