From personal experience 'brilliant jerks' from articles like this and popular culture are people who are criticising everything and everyone as if they know better and are often seen as brilliant by less savvy colleagues (e.g., their managers) but have nothing to show for it and are often seen as impostors by their more savvy peers.

I personally know several truly brilliant people at what they do and none of them are jerks. I have yet to see this 'brilliant jerk' everyone seems to be taking about.