The pool reward is pps so blocks are not necessarily paid at a 10% loss based on luck. PPLNS would be that way.
So when the pool is lucky it breaks even. When the pool is unlucky or has even luck it takes a loss. Over time it takes a massive loss. Several PPS pools went bankrupt in the past, even when charging fees.
If they have a trick or they think they have a trick to stay ahead of luck then it works until it falls apart and in the mean time I am happy with these rewards.
It's not illegal or a scam to throw away hundreds of bitcoins and pay miners too much. That's a whole different discusison.
I've only heard of one pool doing something like this before, and they were "investing" the coins in a ponzi scheme.
Asking questions here is not "stupid questions". Noone is a "complete noob idiot" for asking questions in a situation like this.
"A trick", "business structure" or "rewards in the blocks we solve" makes absolutely no sense. It sounds like a scammer talking.