The newspaper even reminds us from time to time how discrimination of this type is against Chinese law (but then free speech is also protected by the Chinese constitution so....). I made some fuss once about Hep. B carrier discrimination. And let's not even get into minority discrimination (can a Uighur get a job?).
"the location of a person’s “hukou,” or residency permit"
Employers in every country do this and we don't call it "just wrong" (though it is). They use the more international form of a hukou known as a passport.
Western companies also have hiring discrimination based on social abilities and who your friends are, even when it's of only minor relevance to the job. A person's personality is considered worth discriminating against (even for jobs working alone) but that isn't automatically more acceptable than physical characteristics.