Each organism is a unique experiment of nature which creates chemical compounds that can be found nowhere else. We may believe something has no use now, but we have no idea what use it might have in the future. The destruction of an organism now is the permanent loss of an opportunity to find something useful to help humanity. All of life consists of making choices and paying costs. Every time somebody does something it is possible to hurt or destroy something.
Humans have a right to be here and to use the earth.
In a natural system such a species can only exist in small numbers, or it will destroy its food support system. Economic growth is actually a war of extermination on all other species which must be stopped in any way possible. Economic growth has only helped a small percentage of people so far, and has not even helped them very much judging by all the unhappiness in the wealthy nations. Growth for growth's sake will never create a satisfactory standard of living so long as it is based on competition and domination. Growth has not been pursued to make life better, but as a way to gain power to dominate more and more of society and nature.