The lost DPS time for ranged is nothing compared to the dance required for melee.
You have to get out of the shatter, you have to pay attention to the tank positioning after you get back as you may now be in a spot that gets clipped by his ground slam.

Having played this game with a healer tank, ranged dps and melee, I can say only the tank is worse than the Melee, and only just. The ranged was easiest by far, timing a dot is nothing. You never worry about shatter, and even if you get hit with a paralyze, so what? Lost DPS time to that is minimal compared to the time lost eating dirt.

We had an elemental shaman sitting on arcanotron and it was a TON better than a melee. The shaman had a focus macro to wind sheer, and was still doing damage to the active golem. Having a melee do it means worrying about them breaking a shield they can't get rid of and losing pretty much all dps while they do it.

Magmaw with mages blinking in to get on the head so no one but the tanks were in melee range is much better than watching one of the melee get destroyed when he transitions and decided to attack before the tank can even target him. Not like the melee can attack the parasites better than ranged can.

Yes, designing encounters is tough, but making EVERY boss have some stupid penalty associated with being in melee is getting old. Come on, give us a Void Reaver fight!