If a significant number of players defect, the scam as a whole would stop working.

Presumably all competent scammers benefit from being able to repeat the scam, and would lose out if the scam stopped working, so they all have an incentive not to defect.

Scams like this depend on the scammers understanding the incentives better than their targets and so it’s reasonable to assume that the scammers are aware of the context.

However - this is probably true as well:

https://news.ycombinator.com/item?id=23949046