The problems in this case go all the way back to the beginnings of the series. To fix them, the writers would have needed to cast more non-white actors in Main Character slots instead of Supporting Character slots.

The sexism issues were slightly different. The problem there, as I see it, is not so much that the show portrays a society that is sexist in much the same way that ours is, but that they do so as the writers claim not to be doing so. Also they could have killed off fewer of the women.