On the other hand, lingering conditions are generally the result of monster special abilities and spells, not a consequence of losing hit points. And most of these conditions can be removed by casing the right spells. Exhaustion is odd in that it's not something the Cleric has a band-aid for.
A lot of talk was spent on "specific injuries" in AD&D, for example, with Gary going on a long discussion about it in the DMG (in a rare moment of kindness towards those dirty, dirty players). Of course, the crux of his argument is that he was convinced any such rules would somehow benefit the players (?), as if he wasn't cognizant that there are many, many more monsters out there who would be happy to stab out your eye or cut off your hand than player characters.
I think the 2e DMG goes over this point as well, mentioning that if one used injuries by level 5, the players will be a sorry looking lot, missing limbs, noses, eyes, and ears, due to the rigors of "realistic" combat.
That D&D continues to use hit points at all shows that the developers want heroes to be able to shrug off sword blows and lightning bolts and keep on going, like an 80's action hero.
And, as someone said to me not too long ago, "how can the most popular TTRPG in the universe be wrong?". : )