The Profile does not say that he has no children. In the top section it says that the children are unknown but the biography has a list of them with enough information for you to create profiles for them. On WikiTree there is a limit on how many profiles any one person can manage and most of us have found that even that limit is more than we can handle so we are very cautious about how many profiles we create. Most of us concentrate our research along lines that follow our own family, so if you have an interest in James Cooper's line feel free to join so that you can create them.