I question the necessity of it in DAI.
And Witcher 3, from what I've seen, is not a good example of "tasteful and appropriate"
Well necessity is an entirely different matter. Nobody needs to get completely undressed to do the horizontal mambo, but, just like in movies, nudity has an impact on the experience and atmosphere of the moment. If you're having some post-loving chatter, are you actually covering yourself up with blankets as though someone is watching? Probably not, and I'm not going to fault any work of fiction for not adhering to an outdated convention such as that.
Now when I say "tasteful and appropriate," I could care less what your definition of that is. For the sake of establishing some contrast, PC nudity mods are tasteless and inappropriate as there is neither rhyme nor reason to it. However, if you're in a strip club, brothel, or hanging around the home of an eccentric playboy, you're going to see some nudity. Seeing as nudity in the Witcher 3 was mostly contained to brothels, public bathhouses, and romance scenes, I don't see it as inappropriate. It was appropriate in its context and, seeing as no one was bending over and spreading any cheeks, I'd say that nudity was not tasteless either.
The option to not include nudity does not make the inclusion of it tasteless or inappropriate. Given the setting and situations it's used in, there's nothing wrong with including nudity and, considering the age of most of their player base, there's not much of reason for Bioware to shy away from it.