I remember the simpler days when cloth/light armor dps did the most damage, leather/medium armor dps did less, and metal/heavy armor dps did the least. It went the opposite for squishiness. Of course, there were "hybrids" who could wear different kinds of armor and equip a larger variety of weapons; they could also heal, take a slight beating, and do some damage. They tended to scale pretty well with equipment and were usually the envy towards the end of an expansion life-cycle when everyone was maxed out; up until that point, they tended to just solo. The red mage certainly isn't that.

Nowadays, the perception of where dps should stand depends on how many gimmicks a class has, how easy they are to play compared to others (whether it is in their rotation or encounter mechanics", how "needed" they may appear to be in this situation or that situation, and whether they are in this dps role or that dps role. Since SE will never clearly answer the question (because they are probably as confused about it as everyone - nothing was ever outlined or what was originally outlined was never adhered to), the speculation of who should do what and why just gets crazier and crazier.