Times have changed. In the not-too-distant past, prenuptial agreements were not for everyone. The vast majority of people got married without one. The general consensus was that such agreements were only for the 'rich and famous.' In today's climate, people are seemingly more sophisticated than in the past.
The "temporary incompetence" of clients due to their emotional state and the attorneys' paternalistic attitude toward clients create a lack of understanding on the part of both the attorney and the client. This is the legal equivalent of a ship that hits rocks, runs aground, veers off course, and possibly sinks.
The most important factor in mediation success and not allowing the mediator's "truth" derail the process is that the mediator has respect for both clients. This respect should be evident and actual -- demonstrated by words, listening, comments, and structure -- or else the moment of "truth" might be too dangerous.