You seem to have linked the ethics of individuals and a marketing model. I don't get the link. I have no personal affiliation with an MLM except that I did IT work for one early in my career. I have looked at the model objectively and find I do not prefer it. In fact, with the Internet, I dislike most any interaction with a sales person. There are people and cultures that embrace this kind of model. I don't see how ethics has anything to do with it. You went a step further painting the founders as unethical. This would imply there are several Mission Presidents that are unethical in their business dealings as they return to their companies after their mission.

A marketing model you don't like does not make the founders who chose it unethical. I don't wish to get in a fight over this, it's just disappointing to see so many unable to look at this objectively. Or maybe I am ignorant and you can point out what inherently is unethical about this marketing model.