If they made healers into pure healers, would you still play it?

[Sylve]

The OP suggested it.

But I cannot help but feel encounter design is based to work around how healing kits work, because in higher content, you still make those kinds of decisions. I think part of the problem here is that healing kits work well for high end content and are balanced that way but the difficulty jump means that lower level content suffers. We adjust for lower content we affect higher content. This is why one of my previous suggestions has been make raid balance separate (kinda like we do for PvP but not that extreme).

For example, if you wanted to adjust those oGCD windows to make Grand Cosmos more interesting to heal, what impact would that have on Shiva Savage or the new Ex fight?

The solution I support would allow room for Grand Cosmos to be more interesting than it is currently for a healer by giving us more to do when we're not healing without impacting high level content, with a view to make future content more engaging on the healing side.

Well ... Why would encounter design change in Grand Cosmos affect how we use our oGCDs in Shiva?
Once again, Our kit remains exactly as it is right now. But Grand Cosmos bosses would use mechanics in more rapid succession. For slightly less damage per hit, more often.

Turning us into DPS jobs that press a healing oGCD when the script requests it is basically what you're asking for. Lack of things to do except DPS in downtimes is the problem.
The solution isn't more elaborate downtime DPS, its to reduce the amount of downtime we have in between necessary healing.