The question is - why do people get scammed? 
For most of the cases (low-level scams such as ponzi and altcoin IPO), it is because they are gullible and greedy.
But some scams are elaborated and it is not so easy to notice them beforehand.
The next level of a scam, is something like pulling a berne madoff, thats level 2,000.
Where most individuals will give a money to a financial investment firm lol.