And you remain incorrect.
Refusing to use a class ability out of preference when that class ability would be useful to the group is uncooperative.
No, it is
not. If you prioritize story (which my groups do), you cooperate by playing your character as they would behave as a real person. If someone has the vision of, say a devotee of the gods who has devoted themselves entirely to a mission that requires them to become a warlike instrument of wrath (war cleric), they might see that as eschewing healing altogether.
I think you have a much more meta-gaming view of the table than I do, where the players are all optimizing their party composition or something. We do not approach the game that way. Everyone comes up with their character concept and tries to play it. Often they will take suboptimal abilities, spells, or actions because it makes sense for their character, and that makes the game, which is a game after all, more
fun.
You seem stuck on this notion that there is one proper way to play a cleric and anyone not doing it the way you like is therefore being cooperative. At my table, meta-gaming is being uncooperative because we don't enjoy that. People get to choose what makes sense for their character.
Perhaps we can agree that "cooperative" looks different for different groups.
Edit: Also, healing is not a "class ability" for clerics. For most sub-classes, it is not automatically built into their chassis. They have healing magic
available that they can
choose to take. So do bards, paladins, monks, druids, wizards, sorcerers, and warlocks. So, actually, does every other class if your campaign uses feats.