I've talked before about mods that change characters, but I'll reiterate. There are some that I am repulsed by, like the white blonde Isabela one, some that I don't like but understand a little more, like the sexuality changing ones, and some that I have no problem with like those that simply change the colour of outfits and give characters different hairstyles.
I wouldn't install any of the first two categories myself, as it feels instinctively wrong to me, but really I have to take the attitude that this is a single player game and no real person is being harmed, so let people do what they like. I don't believe that playing violent video games makes you kill people in real life, so I can't see why I would think that modding characters makes people think that they can change them in real life. I credit people with the ability to tell the difference.