I appreciate the play reports, it's good to hear impressions despite the NDA.
Anyway, I insist that it's a bug, and it's easy to fix. Just separate a cleric's healing from his other spells. Make it a class feature or something.
I tend to agree, and think there can be an acceptable middle ground. For example, one could build a small value-added domain/sphere effect into spells, and just make sure the cleric has access to it under the right circumstances? (This is basically what I do in my homebrew game.)
In that case perhaps Cure includes a domain effect that allows the caster to make a Heal check + target's Con modifier vs. DC 20, and on a success the creature heals an additional amount equal to 5+spell level? (Obviously the specifics aren't important right now).
Then Vancian divine casters like clerics and priests (?) might be able to cast their "domain" spells spontaneously, but gain the special domain effect only if they prepared the spell. I suppose all clerics would gain the ability to cast Cure in this fashion as a class feature, and so would priests of deities with the Healing domain or equivalent. A cleric/priest could then concentrate on healing if desired, or go for versatility and rely on spontaneous healing to get the job done. Probably most would find a suitable balance with a couple good healing spells memorized for desperate situations. (Off-topic: I'm inclined to keep healing spells powerful and standard actions, and leave minor action "shout-healing" if it must exist to other classes to keep some conceptual and mechanical separation between the two. If the minor action healers are doing their jobs the cleric won't feel the need to cast Cure every round, and when one finally does it should feel like something truly significant.)
A spontaneous divine caster might access such effects in a different way such as spending faith points, expending lesser spell slots, etc. Heck, if a class has a very restricted spell list maybe for them the special effect is always on.
I love this sort of thing, because it adds maybe a line or two to spells, but can help show how a divine caster is specifically empowered in some area. A fire priest has a unique flame strike, one of Pelor has especially searing rays, one of Vecna has and detects subtler illusions, etc. Perhaps a feat can add a separate effect to a few particularly deity-specific spells using the same mechanics, so that it works with all divine casters. Rather like 4e's Channel Divinity, which was a decent idea but had such small scope it barely mattered.
I must admit, I'm a big fan of adding a touch of spontaneity to at least some Vancian casters. Divine characters especially because, thematically, there is a place for preparation and a place for urgent prayer.
Edit:
Blacky the Blackball said:
As an aside, the "Heal-Bot" cleric problem was mainly a 3.x problem rather than a problem of older editions, because 3.x cleric having curing spells at all levels and being able to spontaneously switch to them meant they always had the option of spending their action curing someone and therefore were under pressure from the other players to do so.
True, but before that there was pressure to prepare more healing in the first place, which is why the change was made in 3e in the first place. Perhaps 3e made it worse, I couldn't say. However, the real solution in my opinion is making sure healing can come from multiple characters. This is something that 4e did well, despite my occasional thematic discomfort with how it was achieved.