The "usual how it's not he kids fault" is usual because it's true! It's a common dynamic. Children tend to blame themselves when things go wrong, but your parents are adults, and their relationship was their responsibility, not yours. Often times, moving on is best because it's time to move on. Marriage shouldn't be an endurance contest, and people grow and change in ways that sometimes cause them to diverge. This can be traumatic for children, because they may rely on the marriage as foundational to their world view, but it serves no one to hold that a marriage that ends is a failure. Its success or failure must be judged on what occurred, what was learned, what was accomplished.
My wife and I once took a taxi and we start chatting with the driver. He happened to mention that he'd been married for almost 40 years, or some such thing, and we did the standard "congratulations!" spiel. The bile that he proceeded to spew about his wife, what he felt about her, and how miserable he was left us speechless. THAT was a failed marriage!
