Yes, people lose take gambles and lose out on businesses all the time. But comparing MLMs to regular businesses is wrong. In a regular entrepreneurship, you (the owner) are either producing the product or providing the service directly, as you take in more work and grow, you can hire more people and pay them for their work.

In an MLM, it's a completely different model, in which (to get ahead) you must recruit others who, in turn, must also recruit others. You don't pay people for work, but for who they recruit and how many. Pyramid schemes of this nature generally don't enrich anybody, but those at the very top, whereas with a traditional business model EVERYBODY can make money.

Let's not conflate the two. The vast majority of those in MLMs make no money at all.