Why the double standard?

I'm taking a break today from personal finance and dividend investing for this week, as its been sort of slow with a holiday week.  Please indulge me in a little rant, and go ahead and comment to try and help me see the folly in my thinking:

On the 4th, waiting for a friend to come over, I was watching one of those tv judge shows.  The plaintiff was living with the defendant in a roommate situation, and they had signed a lease together.  After a month, the plaintiff moved out, but continued to honor the lease by paying it every month.  A few months after that, the defendant moved out, however he stopped paying on the lease, citing "lonliness" caused by the plaintiff's moving out as the reason he wasn't honoring the lease.  The plaintiff was suing the defendant for the unpaid portion of the lease, as well as punitive damages, like damage to his credit (apparently this all came to light when the plaintiff tried to apply for a loan, and was rejected due to the fact that due to the defendant not honoring the lease, as his name was on a delinquent lease).

The judge ruled in favor of the plaintiff for the balance owed on the lease.  However, the judge did NOT give the plaintiff anything for punitive damages.  The judge's reasoning was that the plaintiff willingly entered into this lease agreement with the defendant, and knew upfront of the type of risk they were taking on by splitting a lease with another party.  So far, no problem with me, I agree completely with the judge's ruling.

But this is where things get a little murky for me - in the above scenario, replace the lease agreement with a marriage agreement.  Why aren't these things treated the same way?  I liken the fact that the plaintiff was made whole in this case by being given back the money owed on the lease to an equal distribution of marital possessions after a divorce.  But the second part of the ruling seems to fly in the face of alimony payments.  "Well, she didn't make as much as him, and got used to living a better lifestyle; that shouldn't be taken away from her," or "Well he stayed home with the kids and compromised his career to do so, he should be compensated for that."  I say (and apparently this judge might say) SO WHAT?  You willingly entered into this agreement (marriage) with this person here, and made these decisions knowing full well the risk that you were taking on by getting into this marriage agreement.  WHY DON'T WE AS A SOCIETY TREAT MARRIAGE AS AN AGREEMENT LIKE THE ONE IN THE EXAMPLE?  If we're not going to do that, then why are divorces in government-run courts in the first place?  Can anyone help me try to understand this?