I think it's time to admit that dPOS is not decentralized. There are witnesses which make decisions, and people who vote those witnesses.
It is like politics. If the leaders (witnesses) make a decision with consensus then it is by design a good one, a decentralized one.
If you are looking for decentralization like Bitcoin's, you're not going to find it in a dPOS blockchain.
Is that bad? I don't think so. I believe it's a great governance model.