I think that the numbers are smaller on nukes because those are partial resists, and that melee hits seem smaller because players tend to have better AC and such than the average mobs that you are usually smacking up. So dots seem 'better' because they do full damage if they land on the target.
(I'm not positive on this though!)
well the first thing would be to make melee classes be able to hit running toons. Any class can pretty much kite a pure melee class around unsnared, hide far away, cast a dot (dots need to be nerfed in pvp) etc and just keep running around. Sure you can use a throwing item or something but casters land spells a lot easier than melees land ranged attacks. So thats the first thing I'd balance.
I think that the numbers are smaller on nukes because those are partial resists, and that melee hits seem smaller because players tend to have better AC and such than the average mobs that you are usually smacking up. So dots seem 'better' because they do full damage if they land on the target.
(I'm not positive on this though!)