So with everyone making their own threats and me being too lazy to bother with multi-threat discussion I'll do as well, just to get some stuff off my chest and share my thoughts (which, really, is just a fancy way of saying make myself feel better). DDO used to be a cooperative environment in the good old days between healing, CC and (usually melee) heavy hitters (dps/tanks) not because the game was too difficult for a (non-balanced) group of ranged or because archers/casters/throwers had no way to compensate for incoming damage without healers, but because the traditional CC/Heals/DPS combo simply was the safest, easiest and fastest/most effective way to beat every content.

(Non-Magic) Ranged had a defense benefit by operating at range which made them nice to have around if things went south, but could not churn out the same kind of dps melee heavy hitters could.
Arcanes would have higher spike damage than melee, which helped (a lot) against tough opponents and bosses, but could not easily sustain that damage over a full quest.

These days though, Arcanes (particularly Warlocks, Sorcerer and everyone running Shiradi) can sustain their dps with relative ease.
Ranged dps has been boosted to compete with melee levels (especially once you factor the time it takes for melee to actually get from mob to mob).
That put melee really at a place were they had no special benefit, doing roughly the same as everyone else except at a greater risk.

Armor up was supposed to address this but ended up hardly ideal because:
a) standing still is easier than moving, thus making easy even simpler
b) DDO's diversity allowed for everyone to simply slap on a set of heavy armor, hold a shield and use splash levels from other classes to gain the maximum defensive benefit.