It’s not the mining that’s a problem. It seems they’re just reselling the same hashes. The problem is that they shouldn’t have power to validate bitcoin transactions. That power is reserved to bitcoin nodes. Don’t have a problem with federations either. Federations are fine, whether Liquid or RSK. The chain validators are outside the bitcoin ecosystem. No forks necessary. Something happens to that chain, it’s not a problem with bitcoin. You might see it as a fuzzy, but I see one as inside bitcoin and the other as outside bitcoin. Honestly, I don’t understand why DC proponents don’t just create their own federation. It just needs to be separate from bitcoin.