When you arrive at this point in the degraded system, enacting change to remove entrenchment would mean that a voter must pick the worst outcome in the decision trees. Unless a collective of voters can unanimously perform this change at a single point in time, it means that you will end up in a situation where some voter is trying to change the system with real economic opportunity cost by forgoing the kickback from the entrenched positions. It will stay in this poor position until enough voters would follow -- which may be never. I consider this an altruistic effort, as one forgoes personal greed, and it has a tangible economic cost to them.

The social aspect is something I haven't touched on, and it certainly exists. It is one of the reasons I think steem has not devolved in the same way other DPoS networks have -- this type of corruption is much more visible on the social network aspect that is deeply intertwined with the economics.

Ensuring the culture remains anti-corruption I think is certainly key to prevent or undo entrenchment.