Becaouse it's a long and cruel practice killing poor, abandoned and sad animals without owner got to live, sterilised them and castrate for free, but don't kill them. Only becaouse nobody want them. Start great campaigns in media and adopt them.
We human beings and animal friends want to stop cruel death in animal shelters (cats and dogs). That's barbarian custom. Let them live and adopt them. WE WANT NO-KILL SHELTERS EVERYWHERE (Croatia and in all other countries).