How far would you go with that?

It's not the MLM companies who prey on people's wishful thinking. The MLM companies just provide (sell) the products and the compensation plan. It's the distributors who prey on people's wishful thinking. The MLM companies are sellers of a retail product.

The idea that anyone should get money selling their product isn't really the thing they're advertising. The company is selling a product and giving an opportunity for others to sell it for them as another distribution outlet.

It's somewhat similar to bloggers who blog about making money. Most of those bloggers make money by selling hosting services. Are the hosting services responsible for how the bloggers sold those services, by offering people the idea they too could make money blogging?

Affiliate marketing also comes to mind with this same concept. People put out a product and allows other people to advertise for them and make a portion of the proceeds. It's a very tiny percentage. There are other people who then claim that people can make a living doing affiliate marketing so they'll buy the product from them. Is it the responsibility of the person who puts out the original product to foresee that some people are going into affiliate marketing based on the claims of people distributing their product and might not make much money doing it?

If you're claiming that the seller of a product knows or should know how its retail product is being sold, where do you draw the line that voluntary distributors of that product need to be protected that they may not make a living doing it?

How would you distinguish these businesses from businesses that also sell retail products and pay people to distribute those products for them, which is pretty much any product you see on any store shelf? Any distributor of any product has the potential to lose money buying a physical product and not being able to sell it.

Edit: I just looked up consumer protection in wikipedia because I wondered if distributors of product are still consumers. According to wiki, consumers are -

A consumer is defined as someone who acquires goods or services for direct use or ownership rather than for resale or use in production and manufacturing.

I don't know whether the protections of the consumer protection laws work in the same way for distributors.