There's yet another thread over on Dragonsfoot about killer low level modules. Actually, there are two, one specifically about B2 Keep on the Borderlands, and another about low level modules in general.
These modules being 'killer' teach players a valuable lesson. You don't need to kill everything that moves in the dungeon.
Now, I realize that there are benefits to throwing a few softballs toward new players to keep them interested in the game. You don't want to be a dick DM and just slaughter their 2 hit point Fighter with a kobold in the first encounter and laugh about it. Instead, you should encourage them to roll with the punches and get back on the horse when that happens. If you're playing Super Mario Brothers and get killed by that first Goomba, you don't give up, throw the controller across the room, and never play the game again.
With an RPG, especially one that has potentially deadly combats like low level Classic or AD&D, don't encourage the 'precious snowflake' mentality of PCs until after the players have some experience. If you are an experienced gamer, then sure, go ahead and start fleshing out your character before the dice hit the table. You're likely smart and experienced enough to know not to charge the owlbear with that 2 hit point Fighter.
But for people just starting out, get them used to the game, including its deadliness, before you encourage them to really develop those fragile low level characters.
And definitely quash any ideas that D&D should play like Diablo or something, where the goal is to 'clear the level.' The goal is to get the loot, not to fight every monster down there.