Why haven't people realized the bitcoin-esque products are all Ponzi schemes that developers hope to cash in on? If the product has even mild success, the developer has created wealth for themselves.
What country?
It's totally fine not to like it, but it is a system that provides value for many people, and assuming there are more value to be provided from network effect is not a crazy idea (like when a business can have multiple steps in it's supply chain happen on the blockchain).
Zuck doesn't control the majority of shares, he controls the majority of voting shares. If FB started selling shares and using the proceeds of those shares to pay dividends to existing investors then it might be a Ponzi scheme if this were not disclosed in relevant documents.