You're totally right, realism is deffinately the most important thing in the universe. Infact, let's change all ships so they look like space-shuttles, remove all sound
There is no sound outside of your cockpit. (that includes sound from other ships' engines, which is produced in your cockpit by your audio HUD)
remove lasers and projectile weapons (cause machineguns and the like require oxygen to fire)
Machine guns don't require oxygen to fire (the gas-operated ones require gas from the oxidation of the bullet's propellant —not oxygen!— to move to the next round, but mini-guns are electric). And bullets don't need oxygen, they contain their own oxidising agent and can be fired in space just fine.