a marriage can be over in every way, including legally, but that doesn't speak anything about the completion of healing from a marriage breaking apart.
tons of damage is done to the mind and soul of an individual when separation/divorce happens.
Even if you want the divorce and the marriage is completely dead, there are still hurts and vulnerabilities there. Afterall, something drastic had to happen for the marriage to fall apart. Hurt and vulnerable is no condition to start a relationship in.
I don't want my ex back for anything. We have been divorced for almost 2 years. I've had counseling, been ministered to, been in more than one support group, jounaled, written, ...but I still hurt from the damage done in our marriage. I still have mental issues to work on due to the years of junk that I dealt with while I was married.
I'm saying all this to say that no matter how much a marriage is over, it doesn't mean that a person is ready to move on for the next relationship. If a person tries to before they are ready all they will really be doing is moving toward their next broken relationship.