Well, there are objective parameters by which you can determine that.
I could give you a dozen examples.
Photography, art, music. There are objective parameters in each category that determine what is quality and what is not.
Even when concerning quality of text....

But thats not the question really. What i find important is the CHOICE...
The most important change Steem needs is that we introduce choice into our content placement.
Maybe the community is stupid and has a shitty taste in content but it should be able to make that choice for itself. Something which it does not right now.

There is no way downvotes will be used responsibly which more than negates any possible benefits.

But here i completely agree. If there was a way to mask who the downvoter is on a post that would do the trick.
Then you would actually see people acting the way they should. Based on their personal convictions.
If you could encrypt, somehow, the downvoter on a post i guarantee you that bad apples like Bernie, FTG, chbartist... etc would be booted off the platform by the time the community realizes that the system works... I would bet every penny of crypto i have that would happen.

Unfortunately it wont and youre left with an idea that only works if youre incapable of assessing human behavior.