Just a few months ago we were all complaining about how grevious wounds was a worthless mechanic that was nearly impossible to get. It was removed from nearly every kit and Executioners was removed from the game entirely. Leaving only Morellonomicon (which only applies below 40% health) and ignite, which was used 9/10 to kill, not apply grevious wounds. Now all of a sudden in people's minds it was the best mechanic ever and removing it's ability to affect ally heals broke Soraka. Despite that almost no one had grevious wounds and she could easily cleanse them by pressing R.
I think you are right. It was changed because easier access meant the mechanic had to be toned down. But a lot has changed since the mechanic was first introduced and I don't think it needs to be changed back to affecting ally heals. There are 14 champions in this game that can heal allies, and for the sake of simplicity I think we can tone it down to only the champions that directly heal (removing Kindred, Shen, Fiora). That leaves 11 champions (Nami, Taric, Alistar, Bard, Janna, Sona, Nid, Kayle, Zilean, Lulu, and Soraka). The only champion of that group that is broken right now because of their heal is Soraka. The problem is pretty clearly Soraka, who was OP before preseason changes. Mastery and item changes helped her out even more. Changing grevious wounds once again despite being readily available will hurt everyone to affect one champion. That doesn't seem like the right way to go.
's Astral Infusion) was removed because it can be applied so consistently at any health with 
. And as it happens, Soraka happens to be a champion that gets on a lot of people's nerves, even with Grievous Wounds. Why not make the %reduced healing a certain amount for self heals, and a lesser amount for outside heals? Or simply make 
