Ethereum wants to go POS, not DPOS, but this reverse exchange hack likely applies to POS as well, seeing as the exchanges control stake.

I assume all DPOS blockchains will require centralized exchanges to officially register accounts and ban those accounts from governance voting. Only logical outcome of this centralized attack vector.

Dan is an asshole for saying that. His stupid idea of allowing 1 coin to vote for 30 witnesses is 100% the reason we are in this situation right now. We would easily be able to vote in at least 5 witnesses no problem if the voting ratio was 1:1. This would allow us to veto all upcoming hardforks.