I would never rep a MLM company. It doesn't fit my personality. But NuSkin isn't a scam. A scam is something that promises something and doesn't deliver it. NuSkin, Amway, and to a lesser degree Melaleuca promise a possibility but whenever someone has tried to recruit me they are careful to let you know that it is not guaranteed. That isn't a scam and just because you might find it distasteful doesn't mean it is illegal or immoral. When you accuse someone of something they aren't doing you are bearing false witness and that is immoral.
It's just a different way to market things. I've known a lot of people and I've known a lot of people who have tried MLM's. I've never seen anyone lose their life savings or their home over one. I'm sure it's happened, but I'm pretty sure the top companies go out of their way to prevent that because they don't want the bad publicity and don't want to hurt people.