Retrospectives should not be about sharing pain and venting.
Retrospectives should be about getting better.
How do we make sure that we are a problem solving culture and not a complaining one? We use the clearing technique. Every problem must be followed by a controllable action solution and commitment. Dilemma’s are used, if there is a need for the manager to decide, but the team member must give 2 or 3 possible solutions.
Once the team gets used to this, they start coming prepared to the meeting and come up with solutions in advance. After the team gets comfortable with that, the next logical step is to solve the problems as they happen (Lean anyone?) and not waiting for the retrospect.