DieRuhe: Personally I think there should be some sort of notification system when it comes to up- or down-repping...
"You have been down-repped by "X" on (this post)"
Maybe that would help curtail down-repping just because someone's in a bad mood or being a jerk.
Of course, I know that in practice this would be ridiculous and open up a can of worms, but really, with no "accountability" for clicking, to me the whole thing is kind of pointless. You can get down-repped simply because someone doesn't like what you say.
I could say "I like blueberry pancakes" and someone can down-rep me because they don't agree.
There's really just no good way to implement a system like this.
Or, as I've suggested before, just have an option for up-rep and forgo the down-rep. If you're an "ok" person, your rep should rise over time. If it doesn't, that should be all the notification you need that your approach could probably use some work. I don't get the need to "punish" people by decreasing their score.
"Coming or going, you should deny people their fervent wishes, because they are stupid and contradictory." Or something like that.
Downrepping serves a purpose. When someone doesn't like what you say for whatever reason - especially for a stupid reason! - they are free to click the minus button instead of starting a flame war. And that's a FEATURE. It cuts down on stupid. Similarly, uprepping cuts down on "I agree! +1". Rep needs to be noticeable enough that people feel they achieve something by clicking those buttons, and it absolutely does not need to provide a personal and/or identifying notification. The whole idea is to make people who rage to effectively vent that crap and calm down, and people who are the target of the rage to notice as little as possible.
This forum is full of random people, and, to mangle the English language completely, it needs to be more full of more random people. Because it's a commercial forum supplemental to selling product. Some people will go to it in a bad mood. Some people will be jerks. Some people will be so stupid as to not like blueberry pancakes. You can't, and shouldn't, magically get rid of them. However - from a countably infinite selection of ways to implement a forum interface, there are some that have a noticeable positive effect - those are definitionally "good"; and one that has the most positive impact - that one is definitionally "the best".
The fact that you recognize notification is super bad and can't be bothered to think it through and not suggest it in the first place is omgwtfbbqcringeworthy. I honor your desire for notification this one time. Downrepped.