All I can say is maybe the devs are a little slow in the head. I think boomkins have made it very clear we don't like that mechanic and that it should be changed. Don't care how much dps it adds... or in this case loses, we want something that adds something interesting to the existing playstyle and doesn't take away from the synergy that CA has with incarnation. So maybe we need to give them an interesting idea for a 4set because they clearly can't think of a good one atm.
I mean, some fights you're going to take INC and some you're going to take trees, and maybe even others will be good for soul if they fix it up right, but I don't want to not be able to take a 4set because it messes with a talent choice.