Rashi explains the reason why it’s assur to return the lost object of a goy(gasp!!! all the modernishe will flip out!) unless there is a chilul or kidush hashem, is that it shows that you do not value the mitzvah of doing chesed with jews, with whom there is a mitzvah.
By us, chesed is a mitzvah like tefilin.
For them, it’s just being a nice person, and they will jump to do chesed with goyim, toeva-people, and anyone else – even animals.