I help my raid by doing what is needed and when. Of the three healers we have, I am the most equipped to put out DPS while keeping the tank stable and having CDs for heavy raid damage. I don't have to spam PoH for endless overheals to get my job done, and I shouldn't do that.
People like you are, quite honestly, why the spec needs a nerf badly.
You can still contribute significant DPS by weaving in Penance/HF into your PoH rotation. There's absolutely no reason to not DA stack when you can in order to give your other healers something to do and it does your raid no favours whatsoever.
Would you not use PW:B or request that the other healers hold on their CDs so that the meters look more balanced? It's really quite a double standard, seeing as proper DA stacking can result in pre-shields comparable to most raid CDs right now, and that can actually prevent deaths.
You're right though, healers like me highlight just how potent DA stacking is and present a good reason why its effectiveness should be reduced.