MechaPilot
Explorer
I'm not going to say that the discussion back in the day, "Who is making what class? Do we have a cleric" never happened. In fact, it happened a lot. However, if no one wanted to make a cleric and the other players forced a player to do so, that's jerk players, not the game.
Yeah, it was players being jerks; we both agree on that. The next part is where you and I deviate.
I also disagree about game assumptions. Why? Because if you actually look at the mechanics of the game, combat was supposed to be avoided in the first place. Not only is this provable from things like not getting much XP for monster kills but most of it from treasure, getting XP from the monsters for "defeating" the encounter which includes avoiding it altogether, the fragility of PCs, the multitude of deadly monster traits (save or die poison, level drain, etc), but in the DMG it outright tells you that combat is a last resort when "all else has failed".
So the actual game assumptions tell you to stay out of combat in the first place. I understand a lot of player ignored that assumption and looked for combat, and thus felt like they did in fact need a cleric. But that goes back to player choices, not how the game was actually assumed to be played.
There is plenty of evidence that combat was supposed to be a last resort for players. However, it was often supposed to be the first resort for monsters. When nearly everything wants to kill you and there is only one class that can heal, the game is promoting the notion of "Hey, you should have one of these if you actually want to survive." This is especially so in cases where other options were rough roads to take. A first level Thief was quite fragile, but also so inexperienced at stealth that she only had 10% and 15% chances to hide and move silently (respectively). And with poisons doing HP damage, even sneaking and exploring could make you want a healer around if you fail a save or two.