Would you rather work with a contractor who gives you a due date and sticks to it or one you could never be entirely certain of? If the project slips, how good will communications be?
Seth Godin here relates why it's important to keep public events to a schedule. Conferences aren't about the muckety-mucks, they're about the hard-working stiffs who've forked over their cash. Well, the conferences I organize are, anyway.
If a meeting's not about the participants, why are they there?