yya > but it’s not MY logic, it’s a Gemara in Kiddushin 71a, which is brought להלכה למעשה in detail in Even HaEzer Siman 2.
of course
coffee > You don’t know of any goyim that have good middos?
the way I understand it – if you find someone with bad middos among Jews, you should suspect them. Does not say anything about some gyyim being nice. It relates to intermarriages – Jews who marry non-Jews did an aveirah; non-Jews who marry Jew might be a tzadik who tries to find his way to Torah, or just in general hold Jews in high esteem (credit: my FIL). So, ironically, those children who are halachikally non-Jewish might have a tzaddekes for a mother.