The largest group of players are in http://www.mmotank.com/ of Warcraft. Joke except that they are a dime a dozen, dps are in the queue more then say a tank and a healer. They get to cast the spells that makes things fall. They see so many patrons and watch go down in a blaze of glory.
They can also become very myopic on their environment too centered on large numbers to see if the boss is rain of fire on their face or if the tank is wrong to hold agro. In World of Warcraft, the set of digits that play dps is very important, but being aware of what should happen in the Group also falls on their shoulders.
Healers are generally involved in the healing of all with a green health bar, and the tank is normally stuck hit hit the boss. The dps have the luxury to stop momentarily, with a focus on a single target, and generally have a margin of manoeuvre in the observation of their environment.
A good dps realize over time things happen outside the damage meter in time and learn a lot and to adapt with them, while watching the cool things of blasting.Unless you make an instant cast melee attack most of the dps actions require the player to remain motionless.
It would be great if the fighting did not have mechanics that causes changes of land, circles of fire of Doom, aoe mechanics, or only the instances where if you do not move, either die or get out of the line of the healer's sight. A careful dps knows that movement is going to happen.