"Trustees agree that that, during their terms on the Board and for three years thereafter, they shall not, in any communications with the press or other media or any customer, client or supplier of the Foundation, or any of the Foundation's affiliates, or in discussions on community mailing lists, blogs, or other community forums, personally criticize, ridicule or make any statement that personally disparages or is personally derogatory of the Foundation or its affiliates or any of their respective directors, trustees, or senior officers."
That explicitly bans all public criticism. Criticism is good, criticism is how things improve. Sometimes that criticism has to be public to be effective - for example, how can we make an informed vote for board members if we're not allowed to know that they've done various things wrong during their previous term in office (of course, I would expect anyone making such accusations to provide evidence to support them)?