I personally don't like the concept of negative voting on a platform like this. I think it is too easy to abuse and just does not feel right to me.
If it does not feel right to you, don't use it. But why do you want other people to be deprived of this option?
Because you think it will be abused? Maybe it will, maybe not. We can't be sure unless we try. If we don't try some people will be unhappy - we know this for sure. On the other hand, if we try - it might fail but there is also a chance that it will work just fine and everybody will be satisfied.
It already is being abused.
Which only proves my point: there is already a simple way to do the damage you are so afraid of.
What I propose is this: let's offer people a way to do less damage, so that they don't have to do more damage to reach their goal.
I'm not trying to be a smart-ass here: I really don't understand your logic. The damage is already easily doable and some people are doing this. So if we can't effectively prevent the damage taking place, why don't you want to offer a way to make the damage less painful for the author?
Not sure what you're getting at since if I had my way we'd have no DOWNVOTE and the FLAG would pop up three choices for which it could be used. Plagiarism, Spam, or Abuse, and possibly a way to specify FALSE FLAG. If it is a false flag perhaps it could alert the witnesses and they'd have the ability to remove it, and ding the reputation of the person doing the FALSE FLAG.
So I believe it could be virtually eliminated.