I agree it should work that way but a large percentage of marriages don't survive a tragedy... especially one like this.
Example: Brenda starts blaming Damon for not checking on the kids after he found the open door (really I wonder about that too. Don't most parents check on their kids if they find the slightest thing wrong in the house? But I digress). This kind of thing can fester and if the marriage isn't strong to start with, it can break it apart, in my opinion.
Yes, the parents are messed up and bad role models that is true. It is also true that the physical evidence points to the accused.
Both can be true, the parents are lousy and Westerfield is a murderer.
I don't care if they left the kids alone in the house and has affairs with half the world. That does not give the creep the right to kill the poor little girl.
Why defense attorneys are allowed to demonize everyone else around them is beyond me!
The key here is that there can't be any plausible blame lurking in the background. That's fatal. Something as basic as 'who was driving' (in the case of an auto accident) can put the (sometimes undeserved) blame on one parent's shoulders for the death of a child.
In this case, IMO, there appears to be a cloud hanging over both parents. Their sexual escapades may have opened (or made vulnerable) their lives and home to an invasion by a sexual predator who destroyed their child.
If I were either of these wretches, I'd damn sure be blaming the other.
"...I had always thought that tragedies such as a death would bring people closer because they realize what they had, how much they really do love each other and their children, and to appreciate what's left even more..."
In some cases this may be true, but I don't believe that this would be the case as often as not.
I believe that this sort of outcome would be more likely for passive sorts of people, for those kind of people who take a shot to the teeth and respond by withdrawing or submitting.
People who are more responsive, more aggressive, will lash out, sometimes blindly, when confronted by pain and loss of this magnitude.