There is a short and a long answer.
The short one is: they are part of the scheme.
The long answer I would start with a question: What is the business case?
Many times HYIP monitors wouldn’t recommend programs they think are reliable. They would promote them because they are being paid for that. Listings on monitors are fairly expensive. In fact, abvertising budgets represent the biggest chunk of expenses for a HYIP admin.
Often those admins would give a higher priority to payouts to monitors than payouts to regular investors. It could happen that the project is dead already but some of the monitors still promote it.
CRP has never invested a penny in HYIP monitors. I’m quoting one of the CRP managers: “We don’t do business with those wannabe experts.” That’s probably one of the reasons why CRP is being DDOS attacked on a regular basis. But that has absolutely no impact on the performance of the site. CRP hardware can handle that with ease.