Divorce is based on irreconcilable differences for a number of reasons. Irreconcilable differences go hand-in-hand with the concept of a "no-fault divorce." California became the first state to enact no-fault divorces forty years ago. Since then, every state has enacted no-fault divorces. Divorce petitions now only allow two reasons for requesting divorce; irreconcilable differences and incurable insanity. Irreconcilable differences is a purposely vague term that is interpreted to tell parties that courts are not concerned with who is at fault for the breakdown of a marriage.
The move away from fault-based divorce to no-fault divorces made sense for policy reasons. Courts became overwhelmed with time consuming divorce cases and unnecessary litigation in fault-based divorce systems. Embarrassing and private aspects of marital life were discussed in court. Beyond that, there was legitimate concern that courts were determining what is acceptable and unacceptable behavior in marriage with the result being arbitrary decisions on who is at fault. Spouses at fault faced the risk of "punishment" in court awards of spousal support or community property.
With the introduction of no-fault divorces, one's dirty laundry is no longer relevant. Under Family Code § 2311 all the court needs to be convinced of is that there are irreconcilable differences, these differences are substantial and the marriage is beyond repair with no chance of reconciliation.