That is a very typical response. There are so many reasons why couples choose to live apart.
It has nothing to do with a partner treating you kindly or not. It also doesn't necessarily mean two houses—LATs are very creative with how they create space in their partnership.
Divorce is expensive, emotionally and financially—some people decide to live apart and find new ways to connect and romance each other—it's an investment in their relationship/marriage.
While it may not be for you, it works for many people.