This is the most common scam that people easily bite, well, we can't blame those people who are the victim of this kind of scheme because all they just want is income.
Yes, of course, we cannot blame them the "victims" because all they want is more money from get rich quick ponzi schemes. That just sounds odd. How can you not put a blame on them when all the red flags are there. Can you not blame them for their ignorance and, more importantly, for their greediness?
If you are promised a high profit in a short time - this is scam
It doesn't matter if it's long term or short term. If someone guarantees that you will profit, then that's most likely a scam.