Right. And there are 2 models that allow trolling to thrive.

The first one is unsupervised public servers. Sure you can add some sort of vote-kick system in but there have been known to be groups of trolls/bullies who can skirt around votekick systems simply by harassing others as a large enough group to votekick regular players and vote against members of their own group being votekicked. Either that or the trolls misbehave there until they are kicked/banned and then they go to another server or community to get their rocks off -- rinsing and repeating ad infinitum.

The next one is fully moderated public forums or servers. It's quite possible that anyone who does moderate becomes a target for doxing which opens them up to other forms of harassment outside of that community (ie: threatening phone calls, stalking, etc). The risks increase the larger the community is and the more that any changes break the older status quo of that community. Believe me, moderating can be quite a stressful job.

And non-moderators can't really do anything about it because giving trolls negative attention (ie: complaining and hateful posts directed at the trolls) is giving them the attention they crave.

Ideally, gaming communities would have a fairly large, anonymous moderation staff. Many sites like reddit and ars technica have voting systems that can reduce the amount of attention that individual trolls might get, and in addition moderation can be done fairly anonymously if there is a decent sized moderation staff involved -- but there are certain parts where moderating cannot stop trolling or harassment, especially when said harassment spills outside of the community where a troll has gathered interest in a target, and any person with public contact information or who can be doxed (have their real identity and contact information uncovered and then harassed this way) can still be a victim to trolls. The danger of this is higher for someone who is fairly prolific like a site administrator or an e-celebrity like TotalBiscuit.