1. Bitcoin is decentralized, all ponzi scheme are centralized
2. Bitcoin is not selling any fake product or service, it is completely transparent.
3. Bitcoin is over 10 years now but has never failed, the future even seem brighter than now, ponzi can not last up to 10 years.
4. Bitcoin was even portrayed on wikipedia to be for scammers, but this changed, and was portrayed good now.
5. Many goverments against bitcoin before but now they accept bitcoin, there are even over 7000 bitcoin ATMs in the world now, and bitcoin is used for trnasactions like fiats, even used as payment on some online stores worldwide now.
6. The early investors gained, they were the developers but not in a way the late investors will lose, also many early investors sold bitcoin and makes it more realistic unlike ponzi that has nothing to sell. If you get the market right, there is always still profit in bitcoin.
7. Bitcoin is a very good and easy payment method acceptable in many countries now, has any ponzi been like this? No
8.
I think that we need to add another 8 items to this list, which is also important. A distinctive feature of the Ponzi scheme is that it sets a guaranteed profit for a certain period of time. There is no guaranteed profit in bitcoin: here everyone can get a profit if the price of BTC increases, but they can also get a loss if the price of bitcoin decreases.
There are many other reasons to talk about because these are only few, bitcoin is not a ponzi like bitcoin haters are depicting it, it is completely decentralized and transparent, people that want to invest now should not be discouraged, if they learn how the market fluctuates, they will gain but they should also be mindful of the risk. Bitcoin haters should stop misleading people about what bitcoin is because they know nothing about bitcoin.