Interesting idea. I think though that if anonymous votes (on a blockchain level rather than just a front-end level) turns into a thing -- then all the efforts to prevent bid-bot / vote-circles will become substantially more difficult.

Any relatively savvy user that knows their way around a bit of Python or JS could pretty quickly figure out who up/down-voted their posts if the solution is implemented only on front-ends, and then retaliate / target if desired.

I'd be curious to see what would happen if only down-votes were made to be anonymous. That way "value-extraction abuse" could still be discovered -- and then smaller accounts would be able to cast DV's w/o fear of reprisal.

It would also be interesting to see if a threshhold could be applied for anonymity -- perhaps if you DV value is MORE than -1 STEEM, the DV account is now visible and potentially needs to be justified. Up to that -1 STEEM threshold, maybe you're able to cast a DV w/o revealing your identity.

tl;dr -- I don't think voting should be entirely anonymous, as I think it would only allow bad actors w/ bad intentions more difficult to identify and prevent. Interesting potential w/ making small DV's anonymous though.