That's actually a pretty cool feature. It was before my time, so I was not aware of it.
As V8 so eloquently noted, I was half joking, but only half. I wouldn't want people to become reserved, and not share their opinion for fear of being labeled a troll, but it would be nice to have a feature that would put the egregiously habitual trolls on notice.
It was a cool feature. It encouraged people to ignore trolls in order to take part in watching their ignore button darken. Maybe prevented some forum drama.