Collecting free sats should be tempting to the one who currently doesn't have BTC, plus they can use it to buy lottery tickets to win big... I don't understand.
Few scenario that I could think of
1. Some dont really understand BTC / cryptocurrency therefore stop after few tries and never come back
2. Some just curious at first about this new website then stop because they got some better site out there

22 sats (assumed stable) x 5 (free roll) x 365 (days) = 40,150 sats minimum. With only playing five times per day for one year they can earn 40k sats guaranteed, with the opportunity to win more, plus earn compounding interest after 30k sats.
Most people love quick rich scheme , like ponzi

Maybe the ones you get referrals want quickly and with huge revenue.
Everyone love to have higher amount as quick as possible. Anyone that claimed they got alot from this site is the one that have quite alot of active referall. No one could make alot if they just rely 100% on the free claim .