The biggest point is the emotional damage done to the other party in the marriage. Infidelity causes emotional harm to the other party, and also would emotionally harm children. Infidelity is intentionally breaking marriage vows and violating the sanctity of a marriage. Thus the party committing infidelity has in action failed to upkeep his or her responsibility in the relationship and should forfeit all rights. Is it right that after cheating on you someone would be able to take half of your assets and livelihood? As one expert stated, "If your distress is caused by the negligent or intentional acts of someone else, you may be able to file a personal injury claim to recover compensation for your damages." Infidelity is an example of this, and should have consequences. This is not considered in marital asset division in many cases because of no fault divorce, but in reality should.
In a marriage, both tend to be part of the income or one is responsible for the income of both in a housewife type scenario. Either way, both played key roles in building the marital assets. When the divorce becomes final, both parties will need to fund their new beginning. This means both will need access to transportation and money for security deposits or down payments as well as money to survive on till they can support themselves.
In the end, the cause of divorce is almost never the sole cause of one party. If someone cheats, odds are their spouse has something to do with the reason.