This sentiment ignores the competition involved with opt-in governance structures. When DPOS politicians have to compete for votes, and those votes come from accounts that have to compete for tokens, number go up and everyone wins.
Also, with hundreds of DPOS networks in play, if one becomes corrupt people can leave and reenter another network that hasn't been corrupted. Not to mention the ability to fork the network like Hive did to cut out the corruption. There are a lot of flaws with DPOS but it is superior to republic governance in every possible metric.