This is incorrect.
DC uses the same security model as bitcoin L1. That 51% of hashrate is honest on L1.
Except with DC you need 3-6 months of more then 75% of hashrate to be malicious. One can say its even more secure in that regard than layer 1.
It’s the same game theoretic incentive model.
If you don’t trust miners for DC then you’d should not trust bitcoin at all.
Anyways, it’s the risk is opt in for the users. If they are worried miners are all sudden to become malicious then don’t use them. But don’t stop others from using them.
Let the free market decide what a good idea is, true meritocracy.