The limit is only on female athletes with XY chromosome related disorders in sexual development(DSD). Women with XX chromosomes and no DSD (actually women with XX chromosomes and DSD have no testosterone limit, they changed the rules) have no limit on testosterone. Still very wrong of course.

I think they wanted to institute a blanket limit on testosterone for women's athletes but could not do it because of the reasons you explained in your comment, it won't work as athletes obviously have more testosterone.