You are correct that someone has to pay the bill for poolhopping, and I agree that loyal miners should not be the victim of the abuse.   PPS and DGM are great payout systems, however, they are not the only ones that are hop-proof.  The difference between the systems is in variance and the way the payout system handles the pool's luck.  I've chosen this system to allow luck to increase the payouts for the miners. But this does not make this system any less valid or worse.  It's just a decision, do you wish to always get the same payout, or do you wish to get some part of the luck/bad luck a pool has?  Regardless of which decision you take, these systems are fair.

I still have not yet seen that the system we are using is actually hoppable.  Therefore I will closely monitor the pool, and if I see anyone successfully perform poolhopping, I will change the payout system.  I will also change when someone can show me a mathematically proven model. However, unless I've missed something, most people only say that the variance is not stable.   This is correct, but a feature, loyal users will benefit from this...