Count me as one of the people that has a love-hate relationship with hit points. From a story point, I can completely dance along with the concept that they’re abstract and represent bruises and fatigue and such, and that as characters become more experienced their endurance increases and they can go longer and better avoid serious injury in combat. On the other hand, that’s just an after-the-fact story-gamist rationalization of a mechanic that’s really just a hold over from the game’s miniature wargame days. Then again, it is easy to track, and it’s a tangible reminder to the player that their character is in mortal danger as they tick off how many hit points of damage have been taken. I like that part.Now, I don't have a love-hate relationship with hit points, but I do have one with the way hit points are sometimes used. I'm firmly in the luck and endurance camp; I think the fact that hit points increase with level in D&D makes it clear that they are supposed to be completely abstract.
But this leads me to my main point: I also have a problem with the way hit dice are used. If hit points are luck and endurance for player characters, they should be for monsters also. For the most part, they are, in the original game. The fact that combat ability is connected to hit dice makes that clear.
But as new monsters were added, people started to think that bigger monsters should automatically have more hit dice. But supernatural creatures tend to have more hit dice as well, to represent how dangerous they are. So what if a creature is a really large demon? The answer became "add a humongous amount of hit dice" and hit die inflation was born. Also, combined with the dissociation of armor class from armor type, this resulted in the need for more detailed "stat blocks" for every conceivable monster; after all, you need to know the HD, AC, and movement rate for every possible creature, don't you?
Well, no. Because most creatures are going to be mostly the same, except for special powers or attacks. You could improvise all ordinary beasts with a handful of notes. You only need to know what is different about a creature to run it.