My argument would be make all 3 healers fun first before trying to fix them. I'd prefer a broken SCH I enjoy than a non-broken SCH I hate. So SCH working well (by your view) does absolutely nothing for me while I am not enjoying it. I am one of those who complains that SCH is OP despite playing SCH. Though I don't know if it still technically is, but it was definitely in HW and SB. But I'd not be surprised if it still is.
And hey, I defended WHM when people started saying it was fine when it was doing so much better than SCH and AST in new content, because I knew there was stuff career WHM's wanted changed, were unhappy with and were a little shadowed by the fact AST and SCH got immediate big changes, when WHM's was gradual.
We acknowledge that it is a general healer issue to be fun. Honestly, I thought the forums were pretty united on this point. There's a lot of generic threads, but also a lot of job specific ones - AST threads currently dominate with SCH in second. But we need more WHM's complaining if anything if they unhappy. I've been bringing up WHM as I go along as having issues, but I'm not a guy who can really do WHM justice. I've created a thread that's inclusive of WHM, SCH and AST. Billy, who you've also engaged has made a thread that's inclusive of WHM, SCH and AST. As 2 examples.
Without trying to be rude, it's great saying what representation there should be in the threads on the forum, but I don't recall seeing any you've made. I made one about healer downtime because I felt that one of the more prevalent issues across all 3 healers, although I don't think I am the best representation out, there, I made it and I made it with that disclaimer. You're a WHM, we lack WHM threads, if you think there's reasonable feedback you can give on improving WHM's, by all means jump into the generic healer threads if you not already & start a WHM thread too, if any WHM's lurking they may chime in with their own thoughts and feedback.