In my grandmother Edith Wilson's family everyone had a lot of children so using Presidents or famous people may have been for convenience. I know we had difficulty in naming our children and we only had two.
Edith's father was named after Benjamin Franklin. He named one of his sons Abraham Lincoln. He had a nephew named Grover Cleveland Wilson. That's not a President's name you see very often!
Some of the boys in the Wilson family had family names that were passed down from one generation to another. Jasper, Leroy and Moses were repeated in at least 5 generations over many branches.