Yes, it's totally understandable that a person would not want to go back to scratch to raise kids again. While I know people who have done so, I'm sure not everyone would love the idea.
Add to that the fact that your kids are, by your own description, "very wild" and I can clearly see why he's not open to the idea. Thing is, once kids are involved, it's no longer about just you and him and love. It's also very much about how he feels about your kids and parenting style.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.