It good that we are thinking about this.
i think overall downvotes are bad. They tend to create a lot more damage then good and create really bad user experience.
We have lost many great content producers because of downvotes.
I urge you to keep this in mind.
Even if I just get 20% if my voting power as free downvotes, i can now run around and take money away from people and would have to do this, in order to maximize my rewards. This will lead to people downvoting each other and will create a culture of downvote wars, that can be nasty.
Please keep this in mind.
Bad user experience exist because people are so greedy that they think about potential rewards as if they were their already. They aren't.
Steem users decide what content should be rewarded more (by allocating positive reward shares) and what should be rewarded less (by allocating negative reward shares).
Because in first case they are directly rewarded for such choice (via curation rewards or in case of self-voting also via author rewards), they tend to do that much, much, much more frequently than in the second case.
It's far easier to accept "random" upvote than "random" downvote.
Downvoting others wouldn't maximize your rewards. It returns potential rewards back to the pool so they can be shared by everyone. Moreover, community would be able to respond to "unfair" downvotes without cost (to some extent, i.e. % pool)
In the end, Steem is all about reaching consensus, in this case consensus on value of post, thus how it should be rewarded.
We are not ripped off when our content is downvoted.
We are ripped off when our Reward Pool is ripped by abusers.
Who was I abusing in this post reply thread to have been downvoted so hard? My comments were dissenting, nothing more. Bots were used to give more weight to my words, but in the case above I did not use that bot. Someone else did because their vote weight was not sufficient enough. It wasn't self-voting. It wasn't abuse. It was just an opinion someone with more money didn't like.
"Abuse" is a bit too strong of a word this case, but people have spoken that they did not find your content worthy of rewards.
Yes, value of dissenting opinions is also important and should be partially preserved, but in my opinion (speaking for my own downvote) stating that "Weighted Downvotes = Theft" is too ridiculous to be rewarded on par with other content. Other people are free to decide otherwise.
And regarding weighted power... I agree this is not ideal, but I can't think of any other solutions. Either the "best" guys have the most power, everyone is equal or something and between. In the former case there is at least some correlation between a person's (or, sadly, bot's) "quality", leaving abuse opportunities for "the rich", in the latter there are abuse opportunities if you manage to get a hold of a large number of accounts.
In my opinion the weighted option is better.