The first time someone went back through my posts to give me a handful of revenge dislikes after a disagreement, I took it personally, even wrote to the staff about what the policy was for that sort of thing. They didn't even answer, indicating to me that they're just fine with it.
So, okay. It's not really that big a deal, nothing got bloody, I didn't lose any money or sleep over it, and there's really no sense complaining further or taking it to heart... The guy's mad at me. Big deal. Maybe now he feels better. Good on him.
After that initiation, now I just don't care. I use it when I disagree with something someone wrote, especially if it's just blatantly untrue or bad advice, and I get it used on me occasionally as well. Que sera, sera.
When I give it out, it's just a quick way to express disagreement without feeling any need of getting into the weeds about it and pulling up and shaking those weeds and flying dirt into each others' faces that all too often derails the thread into an argument between just a couple of members, the details of which are really inconsequential anyway. Instead it's just a way to signal, "I disagree. 'Nuff said."
I think it's also gonna say something after a period of time when most people have ratios that are heavily positive over negative, and just a few who have ratios that have way too many negatives compared to positives. Not gonna be too hard at that point to know who the helpful folks are, and who's just an ass that doesn't warrant much attention when advice and recommendations are being posted.