The karma function is imho useless. I think the function should be removed.
No one knows, if you got karma for negative or positive help and inputs and so on.
The numbers of karmas does'nt tell how helpful you are, or about the quality of your help, or about how many things you have helped with and so on. A negative number does'nt even tell anything you can use. Why give negative Karma at all?
Karma from one topic does'nt tell anything for another topic.
And yes - some people use it for personal dislikes and such too. That's not useful at all. It's not professionally and objectively, and therefor no help at all.
A help forum should mainly be about help, and the karma function is no help at all, and can even be the opposite. Beside that a forum is also about discussions and ideas and critique, but why use karma in those threads at all, as it only can be used to like or dislike a comment or idea. It does'nt tell anything of any use.
Unfortunately no one can guarantee the Karma is about positive help or attempt to help to solve a users issue only.
Some get addictive to get positive votes, and is very annoyed by negative votes. And that can affect someone in very bad ways, especially as noone can see who voted and about what. That's it. I don't like it, and i can't see any point in having it in a forum like this.
If anyone wan't to give some kind of feedback to anyone, then they can write it in a post in the topic it's about. Then everyone can judge that for them self.
The Karma function has allready been broken some times, so we are some that lost karma and that perhaps more than one time, so you can't count on the numbers anyway. - (A short while ago i think i lost about 15 karma votes from one day to another under website maintenance, so my count is wrong, just to give an example.) - And even if the numbers was correct, then you can't use the vote numbers for anything useful anyway.
What is the Karma function good for?