I *don't* want to scale back the ability of people to make their toons unkillable gods with IOs and Incarnates. I *like* that. I can make my support toons just as unkillable. That was the promise of the first mission of Mender Ramiel's arc, and I'm happy with how it is fulfilled.
All that is required to "fix" the endgame is to make harder enemies (Carnies, Rularu, IDF, etc) worth MORE XP than easier enemies (Council, Romans, and so on) so that people WANT to run the harder content which DOES call for having Support toons around. Then continue to make content that is hard enough it calls for Support even with kitted out Tanks and DPS.
I do think the change that just went in to Rooting, allowing Buffs and Heals that don't interact with enemies to be cast while moving, is a great change for Support classes. More of that, thanks.