The Mythus game introduced the Accursed, "enemies of humanity", and, in fact, the unpublished game Unhallowed was going to deal with this in much greater depth.
Why bother with such a group? Is not an arch-enemy formidable enough? Yes, sort of. There reaches a point, however, when said arch-enemy's escapes stop being believable. This becomes a double problem if the HPs travel from dimension to dimension, hopping from genre to genre. But if the villains are tied together through a loose network, they can be defeated, and yet more is happening, and newer, worse villains can be brought forth believably. Or, the villains can become the thread linking the various genres, as players hop from HardWired to Chaos Changeling to Mythus, and so on and so forth.
Does a group as evil as this have a place in a Cyberpunk setting? Of course it does, that should be plain. However, the Accursed generally operate via magic and evil beings. In Cyberpunk, such stuff is usually the domain of mythology and legends. (The reader is referred to the section on cross-genre play for an alternate approach.)
In HardWired, the Accursed take on behind-the-scenes roles. They finance certain corporate activities, and perhaps some research labs; if one wants a truly illuminated game, they could be a grand conspiracy, secretly pulling the strings of world governments and corporations.
Some potential roles for the Accursed:
Having such a bunch of villains can add continuity to the campaign, and can do something rare in the true Cyberpunk tradition: give the HPs a reason to believe that they can make a difference!