Some people who go into ponzi schemes are ignorant of the dangers associated with it, they think is a better way of making fast money and getting rich quick. Ponzi scheme is a trap to defraud people who would invest in them. They have their way of luring investors in, they offer huge rewards within a short period of time , and claims to be legitimate. We have had about many of these platforms that had existed, and collapsed after gathering enough money from their victims. Another thing is that some people already know they are going into ponzi schemes but they would want to try their luck saying before the platform will collapse they must have made some money, and by the he time they try, they would be traped their untill they loose their money. So it is necessary you don't venture into it at all so that you don't regret later.
Some people are truly ignorant due to lack of knowledge, financial knowledge to be specific. They believe they are making genuine investment with genuine ROI based on how the scammers present it to them. Like you said, the other set of people are well aware of it but they still want to try it anyway thinking they'll enter early and exit before it collapses. They want to outsmart the scammers not knowing that scammers are always smart with their plan. They know how to convince you and get carried away, they know when to pull out.
Some people choose to be like that, since the only thing they want is to gain money from they think easy platform. Also usually those greedy people ignores warnings, that's why many of them got scams despite of numerous warnings about those ponzi platforms.
Hard to learn a lesson in hard way. That's why its good to do a research to avoid such tragic incidents.
Its good to learn from other mistake, rather than learning on ours.