There would be such a solution if users were able to adjust the weight of downvotes or if the vote mechanism was changed to include a mandatory category or reas

There would be such a solution if users were able to adjust the weight of downvotes or if the vote mechanism was changed to include a mandatory category or reason, i.e. '-1 spam' or '-1 disagree' or '-1 flamebait'. This, in combination with a way to adjust the weight of those categories - i.e. I would give 'disagree' votes a weight of 0 since I don't care whether someone else agrees as I like to make up my own mind about things - would make it possible for those who like to downvote from the hip to continue doing so without ruining the discourse for others. Such a system would quickly be gamed by the downvoters who would start marking things they disagree with as 'spam' so another layer would need to be added in which certain types of downvotes - spam, flamebait and other such categories - are checked and undone if needed. Downvoters who abuse their voting privilege too often would loose it for a day, then a week, then a month, etc. In other words, something like the Slashdot moderation/meta-moderation system of old.