Music videos like "Wrecking Ball" do go too far. When people are nude and licking various metal objects, that is rather disgusting and they have gone way too far in getting their artistic point across. Videos like that have crossed a certain point where then the work that they are doing is no longer artistic.
Miley Cyrus is just another child who has grown into woman and wants to flaunt it in the name of creating a scandal. She's not the first person to do this; Britney Spears comes to mind. Miley will not be the last either. Videos like "Wrecking Ball" come and go, and it is tame compared to some of Madonna's videos.