This narrow definition of love excludes forms of love which are not blood-linked and do not have an inherent desire to reproduce.
By this definition, same-sex couples would not be able to experience love. Nor would an adoptive parent for their adopted child. There would also be no room to love a friend or a pet. Love cannot be reduced to reproduction and science. It is far more complex. Sometimes, as in these cases, people love just for love's sake.