Yes, in fact all HYIPs (with the rare exception) are pyramid schemes. Of course you cam make profits from it, but the only guaranteed winner here is a HYIP admin (if he/she/they will not get found )
Far not everyone wants to deal with all the stress involved in running a HYIP.
One must be very paranoiac, clear each step and have to take alot of responsibility for others ppl money.
I'm not maintaining all the support tickets work, payments, ddos and hackers attacks..
I know I'm getting my stable HYIP income for a while, that is enough for me