If it's sexist(Wikipedia definition, yeah... I looked it up) then it's unethical, and if it's unethical I'd assume that's because of the sexism.
Is it unethical and sexist? If it is, being overtly sexist/racist/classist and supporting it with data seems worse to me that just the former. Even it it is, it should surely not be outlawed.
I tried to avoid confusion by referring to the Wikipedia definition, which by my ethical framework pretty much always unethical, but should very rarely be outlawed. It would be a nightmare to validate.