I can agree with pretty much everything except this.
Contrary to popular belief, I don't think the devs are "out to get us." Or that they enjoy seeing us suffer. Or anything like that.
I think they have some serious concerns about the ease with which you can complete certain high level quests.
I mean what would you do? Someone walks into your office and goes "We were dumb. We didn't realize they could use <insert incredibly effective tactic> to essentially walk through the quest with little-to-no-risk. What are we going to do?"
Any major change and you've got to spend some time QAing it (and suffer the wrath of the "OMG Why'd you spend time redoing a quest when you could be making new stuff" people). In the mean time people are shoveling loot into their backpacks.
So I guess, to me, it seems perfectly understandable to make a quick change that cuts off a particular tactic. Everything else that anyone's suggested doesn't seem to a) work or b) be any better. Doors? What exactly would that do? You'd open a door, drag things back, and run on to the next door. Leashes? Then you could just run past the shadows in the first place. Resistance? People would just use the same tactic, max/empower their Walls and it would just take twice as long (which would inevitably lead to people complaining about that).
I don't think what they came up with is the most elegant solution. But I do think it's the solution that probably works the best that involved the least amount of Dev time.
I hope they can watch what happens in Vol, just like they're watching the Abbot raid, and make some adjustments in the future. But honestly, I can't even think what they should do differently. (Aside from maybe naming them something different and/or giving a reason for them to be immune to fire.)