Just like freedom of speech, downvotes can be abused (I made a video discussing this not too long ago). I have been on the receiving end of downvotes and I know how painful it can be, but it plays an important function in curtailing the activities of bad actors on the chain( well, depending on the size of the fish). And like you pointed out, often than not they are discontinued.

I see downvote as a necessary evil. A tool in the hands of huge stakeholder to curtail abuse of the reward pool. The issue has been about defining what is downvote worthy or just plain malicious behaviour and who defines it.

One of the fundamental flaws of dpos is that numbers or should I say individual voice don't matter (that much)--stake does. One person by the virtue of the stake they hold can have the voice of a thousand persons. Most of us from a democratic background consider this as unfair. But on the flip side, we also need to take account that without major stakeholders the hive token would be worth nothing. so if you want better representation you should buy your stake. the system isn't necessarily designed to be fair. freedom isn't cheap. I know in modern times we are made to think otherwise but it isn't.

how can this be fixed?

1. With a stronger middle class we can be able to offset malicious downvotes;
2. The community can set up a (conflict resolution) counsel of some sort to look into supposed bad actors and resolving issues of this nature;

In conclusion, I don't think downvote is something we should do away with. For those of us who have been here long enough, we can attest to the fact that its merits overweight its demerits