Statistics of bad outcomes of divorces need to be compared not to the happy marriages, but to unhappy marriages that did not end in divorces.
One thing to consider: according to R Twersky, if one parent is abusive (including verbal) and the other parent does not stop the abuser (maybe because s/he can’t), children might later forgive the abuser (it was beyond his control) but blame the second parent for not standing up to it.