When people like Quickseller or Vod do it over and over during a period of months
I'm not sure what happened between you and Vod, TECSHARE, but I observe two differences between Quickseller and Vod:
1) While Vod is out to get people who sell microsoft keys, he makes no bones about this. It's his stated motivation and it's easy enough to remove him from your list if you're not worried about microsoft stuff
2) Vod seems to admit that sometimes he's wrong or hasty, he even has a link offering people to remove the negative trust he gave them if they stop selling the keys. I've never seen quickseller back down on a single point or admit he was wrong, ever.
To me, those differences are substantial.
If you actually care to know one of the many reasons I take issue with Vods behavior, there is more than you care to bother to read here:
https://bitcointalk.org/index.php?topic=915823.0;allIn short I criticized him openly for being abusive of his position of the default trust, and he proved he was not abusive by leaving me a negative rating claiming I lied about him. It just started out as me talking about him but then he took the offensive by harming my trust rating because he did not agree with my opinions. Rather than debating it on the forum like an adult he decided he would rather swing his weight around as usual and again abuse his position to attempt to intimidate me into silence.
I believe Quickseller is guilty of the same type of behavior, and in fact I have seen Quickseller change his ratings and admit he was wrong more than once (not that it excuses it). On the other hand Vod usually just blocks people whom he negative rates, and refuses to talk to them for over a month even if he does. I Wouldn't describe that as tolerance. I certainly have only seen him change his ratings a handful of times, a very small percentage of the negative ratings he spews out endlessly.
In the end both of these users engage in "scambusting" as a method of pumping up their own trust ratings which then gives them even more power to abuse users. This is nothing more than another method of trust farming only at the expense of other random users getting caught in the mad dash to collect trust ratings.