I think the point is where the criticism is aimed and how it is made. First to be dispassionate yourself by not being wed to your desired outcome and to ask questions of the "other" party that should lead them to your view if they do not have a rational reason for their view, and they are rational. Second criticise the ideas, not the person or organisation. In that way the ideas fight it out, and you don't get injured, and you award a medal to the winning idea.