The vast majority of Work From Home opportunities online are multi-level-marketing programmes.
It is incorrect to say that these are scams but I can understand the suspicion around this particular business model as it is usually promoted badly, takes all kinds of people from all kinds of backgrounds and often throws them into an unhealthy battle for attention which results in unethical and dishonest advertising habits.
There are many ways you can work from home to enjoy a regular wage or income from your efforts such as freelancing for specific tasks (GetFreelancer is a good site for this and you can register free I think - but it is very competitive).
Work from home opportunities (Multi level or other) offer a viable business model if you take this approach;
1. Find the right company and research it thoroughly before stepping off into the unknown.
2. Understand that it will take a budget to build your business - either online or offline - its a business after all
3. Study and acquire the skills to market effectively
For every person who does not want to buy your product or join your opportunity there are others who do.
Dont try to convince those who dont because its not what they are looking for - find people who are searching for what you are searching for - an income from home and learn how to teach those people how to do what you are doing and you can build a good income over time.