But that is not reality. They aren't buying the products only as some kind of investment. In many or most cases they actually like them and want to use them.
You don't talk about how 100% of the people who shop at Albertsons lose money. They don't. They buy products and the value of the products (to them) equals roughly the $$ they spend. This is not conceptually different.
It is true that MLM products are often over-hyped and over-priced but plenty of people pay $100K for a Tesla when they could easily get by with a $5K used Honda Civic. I don't think your analysis holds at all.