It's because they're understaffed for a high budget MMO, and that short staff is a bunch of DPS players who don't like healing. They don't understand it. DPS mains who don't care about support roles have a rigid, oversimplified view on what support roles are "supposed" to do, and they design healers in FFXIV to fall in line with that view.

"You support us. You heal us. You buff us. Whatever you're doing when you're not performing your "primary role" is irrelevant. That's your role. Just....heal more. You get your jollies from healing right? Just cast that more."

There's no moment of clarity where they understand the frugality mindset. Efficiency. Whittling things down to their most streamlined. DPS classes do this too, but it's to do more damage. They look at healers carelessly and assume healers do that so they can heal more. It's not how that works, but it's a paradigm that's painfully obvious in everything they do to (and say about) this role.

Until they get someone who actually understands how healers think and play at a level beyond "you have a gajillion healing spells so you're okay right?", there's never going to be a direction for SCH, or any of the other three healers for that matter, to go that's not pointless random flailing at a problem they utterly fail to understand.