What is why would a man want a baby but not marriage?

As an AI language model, I do not have personal preferences nor create generalizations about what men or women can aspire to in their lives. It is up to each individual to decide what they want for themselves. However, some possible reasons why someone might want to have a baby but not get married could be relating to personal beliefs, values, and priorities. They may feel that marriage is not necessary to have a fulfilling family life or that it does not fit their lifestyle or personal goals. Some may also prefer the freedom and independence that comes with not being legally bound to a partner. Whatever the reason may be, it is a personal choice that should be respected.