Correct ranged combatants do contribute. They do have to do some meleeing in a quest because of their dps deficiencies but they do contribute while ranging and they will provide an extra dimension if played well. I collect arrows and use arrows such as slaying arrows and +5 holy arrows. Archery in ddo is for the committed it is not for some happy go lucky guy that wants to sit there with a substandard bow and shoot arrows at all the mobs. You have to break out the special arrrows work at lining up your improved precise shot and be willing to do some meleeing. Exude versatility. I also have close to no fail heal scroll umd (someday will get no fail heal scrolls) and want to try to do what I can to help in the scroll usage end as well.
Should they improve ranged dps - the answer is yes, but they are very very afraid of making ranged combat the only way to go by over enhancing it. I think they feel if they ever did that they would kill ddo because so many people love to play melee.