Would tanks be okay if SE swapped the damage between tank and healers?

[Nezerius]

It's the same mentality with trying to nerf Warrior countless times despite how it hasn't been working at all for years. Nerfing is easy and requires no brainpower or effort, see something good? Hit it with the hammer, it's totally not going to just make everything unfun if not cause problems in the future.

The way I'm interpreting the OP, is that it's more of a rhetorical question, rather than a mentality of "nerf everything fun!". It's to put tanks into the healers' shoes, and if the hypothetical situation would affect how much fun they'd be having. Your almost instant "no" answer makes it all the more obvious that tanks would not enjoy having their dps output swapped with the healers.

While you've mentioned that making adjustments to one role at the expense of another isn't the right the thing do, that's essentially what they've been doing with tanks. The increasing amount of self-sustain & party-wide system given to tanks directly impacts the amount of sustain that would otherwise have been provided by the healers. To add an example to this: earlier expansions had people challenge themselves by only bringing 1 healer, and getting the most out of the party-wide sustain provided by said healer. Fast-forward a few expansion, and tanks have gotten to the point of providing this type of sustain to the point of being able to replace that 1 healer with either another tank or another dps.

You're pointing out the "poisoning of the well post that just screams "I'm out of ideas, someone else give me an idea" ", but don't seem to realise that healers have been fighting for role improvements for several expansions. If tanks were in a similar situation, I'm sure you'd eventually start running out of ideas too. And to drive this point home, I'll refer to Supersnow845's signature. That's no exaggeration, it perfectly sums up how healers have been handled over the past 5-6 years, and telling them that 8.0 will be shaking things up will likely make at least half of the healers roll their eyes. They've heard the "wait for the next expansion" way too often.