There is no doubt always hostile members of a community, even those who really enjoy getting on the nerves of others. I have seen several methods to deal with this, from heavy fisted to extremely lax. I personally moderate for both 2K and EA and their communities, and each company has a completely different viewpoint on how to handle things. I've also been an administrator of several other game related communities, and what I've typically seen is that in most cases the only way to initiate change is to lay down a blanket of fair but reliably enforced rules via community support staff.
Trolls and those who choose to flame typically grow like weeds, the more that they get away with things, the more destructive that they become. If a community manager and a team of moderators are granted the ability to enforce rules, and do so consistently, those that will simply not modify their behavior ultimately end up being purged. With some of the most hostile members serving permanent bans or temporary suspensions, the general community has less abrasive talk to deal with (and to defend against / attack), and over time things become much more civil. In turn, the kind of members that you want to have in your community tend to stay.
I've seen arguments both ways where if you're too tough the community diminishes, and if you're too easy the community degrades into a l33t speak filled flamewars. There's really a solid middle ground though that can be achieved by proper staff and sufficient punishment systems. For example, 2K supports an infraction system which allows for several levels of warnings prior to a temporary or permanent ban. Very rarely is anyone dealt the banhammer, primarily because the punishment usually fits the crime so to speak.
So when I hear people say that you can't change the "internets" as if Brad's efforts are fruitless, I immediately disagree. The truth is you can change the community which you lead on a micro level without too much effort. Brad is not looking to change the world, he is only asking that the local community here which operates on the forum which he owns behaves in a respectful manner towards others. That is entirely possible.