I have written quite a bit about DVs. They can be effectively used to combat 'bad behavior' such as spam and plagiarism. However, free DVs represent an avenue for abuse by whale accounts that makes them unsuitable for Layer 2 (i.e. tribe) use, imho.

Tribes should use the 'mute' feature to combat abuse and either do away with DVs altogether or make them non-financial (i.e. a statement of disagreement rather than a financial penalty) or make them costly (and also further reduce the available # per day).

Removal of DVs on Layer 1 will need to wait until a suitable alternative can be devised for combatting plagiarism and spam (which I believe will come, eventually).