One of the fixes that needs to be done across the board for melee is this
(and this is coming from a supposed tank, I play a paladin)
1) increase melee's damage resistance
I know many of you will say NO WAY but listen to this
As it stands now- as a paladin I CAN WEAR CLOTH armor and take BARELY anymore damage than I take with PLATE.

Boss specials hit SO HARD that it DOESNT MATTER who your agro magnet is-- the party healer STILL HAS TO SPAM HEAL him to keep him up

This is relevant to melee DPS because they all take huge amount of damage if they stay to DPS during specials.

So my solution is to to give any melee class an inherent damage mitigation % in dungeons such that they take X amount less damage than ranged characters. My value for X is 60-70 as these bosses hit for absurd numbers.

This would allow melee DPS to stay in and DPS.
The damage mitigation as it is right now in this game is terrible for every class, but it impacts melees more.