Psykers typically in the setting. The general consensus is that any player who cannot find a use for a "cursed" merchandise isn't trying onerous sufficient. Another cursed sword (which makes an appearance in Baldur's Gate) actually gets a bonus to hit and harm to encourage people to make use of it. Similarly, the 3.5 DMG goes so far as to listing a sword that enrages the person as being boon or bane, depending on the wielder's own views.