In the context of a fight it's rarely effective to heal a downed character when you could be attacking the enemy that just felled him. Casting a cure spell without doing anything about the enemy is likely to just get both characters attacked. The best defense is a good offense.
That might be true. If it's just the two of you, and you (the healer) have that good an offense. Or if you're (the healer) the last one to act before the monster goes again, and might drop it. And if the monster is certain to hit before the ally acts and certain to do more damage than you can heal. That's sounding more like the 'rarely,' to me though. :shrug: Then again, if your healer is consistently able to drop any given monster in any given round of any given fight, he just might be "CoDzilla." In which case, sure, stow the Cures and bring on the radioactive breath.
Conversely, out-of-combat healing represents a dump of healing spells and wands that can easily be accomplished by a majority of characters in the game,
Nod. Starting a combat at less than full hps was prettymuch a choice out of the lowest levels in 3e. In 1e, monster damage was low enough and healing resources few enough that you'd sometimes press on wounded, though it was a great way to get killed or put out of action for a week. ;( I got the impression that 4e healing surges were prettymuch there to replace the cheap WoCLW phenomenon with something that would serve the same purpose (full hps at the start of most fights), but remain a more balanced resource accross levels.
Whether you heal to preserve allies' action in-combat, or carry the fight yourself and wake them up when it's over, D&D magical healing is still commonplace (clerics, clerics-in-sticks, guzzling healing potions like gatorade), frequent, and not at all special.
and 3e revised natural healing such that anyone could recover their full allotment of hit points without external aid in very time-efficient fashion. Healing is thus not a huge consideration in character creation, though in the 2e era it was moreso because natural healing was not so generous.
I know 1e natural healing was extremely slow, and 3e hp/level/day healing was faster (though it oddly boiled down to large HD and CON bonuses making you take longer to heal), but still not so fast as recovering spells, casting them as Cures, and resting again. If the DM was at all guarding against the dreaded "5MWD," natural healing would be prohibitively slow, and the prep-cure-prep cycle would probably be a rarity, too. Monetized healing would be a must.