Okay, first you need to distinguish between Multi-Level Marketing (Direct Sales), Ponzi schemes, and pyramids!
1) Pyramids are illegal.
2) Ponzi schemes do not involve a product that people get for their money. Madoff had a Ponzi scheme - people paid money but got nothing back. The top investors got paid with the investments of the lower-down folks.
3) MLM doesn't "depend on others to make a profit" any more than any other brick-and-mortar business. My supermarket doesn't make any money unless people buy the stuff on the shelves! Neither does my lawyer or my doctor or the local movie theater. There are good MLM companies, and a lot of terrible ones. There are good/bad restaurants, good/bad department stores, good/bad stockbrokers. And all of those companies have a lot of levels so they are multi-level as well! Take the supermarket - between the farm and the consumer, we have the many layers of harvest, food broker, manufacture, packaging, transport, warehouse, advertising, overhead, staffing, materials at point of sale, bricks & mortar, and much more. And if the CEO is making a lot more money than the worker bees, and the worker bee has NO chance of making a lot of money, it's a corporate model with is the worst pyramid of all. If, on the other hand, distributors make more money that the president, if they can rise up based on their own efforts rather than corporate largesse, then you have a great MLM company that exemplifies terrific values.
Some of the best companies are MLM companies - Mary Kay, Avon, Fuller Brush, Reliv, and many others. Check the Direct Selling Association for the top 200 companies invited in for their ethical business practices, good compensation plans, and happy distributors. And find out how they've been written up in the nation's business magazines. You can always find something negative on the internet, but that's often from disgruntled distributors or people who've been kicked out because they were unethical. Use objective sources. For example - if Business Week and Forbes have written them up, if Success From Home magazine has featured them prominently, if they have a high distributor detention rate (15% is the norm, so if you find one with a 50% or 60% retention rate), that's awesome. (Most regular companies can't claim that they have kept 60% of their employees over 20 years, for example!) Are bonuses only for those who have been in the company for a long time, or is there a pool of bonus money open to new people as well? Do some people make more than the person who sponsored them? If so, that's a GREAT company where people get paid for what they do, and all the money doesn't go up the line!
Your husband may be in a bad MLM and you should definitely investigate. It's not just whether people are getting a product or a service for their investment. I'd look at the up-front investment ($25 is great, $15,000 is ridiculous), whether that investment is guaranteed (e.g. a 1 year 90% buy-back is phenomenal), whether there is FREE training, whether there are unreasonable restrictions on commissions and overrides and bonuses such that those often pass up to the upline or (worse) the company if you don't do a b or c, if there are quotas and monthly minimums, and a lot more. Is the company publicly traded? If so, there has been no complaint by any of the 50 State Attorneys General. Again - go for official information and not random internet claims.
A crying child is normal - that doesn't make him wrong. But threatening divorce and the public stuff is wrong. Leave your FIL out of it for now - that's going behind your husband to involve his father.
I think your problem is communication with your husband. If you want more help identifying things to check about the company, let me know.