I think it makes a lot of sense. A character who has slain hundreds of "goblins" should not get the same experience for camping and waiting for respawns of them, as a character who slays his/her first.
This was a fault with many RPGs, where you could camp for more powerful respawns that yielded loads of experience - this would in turn make you yourself very powerful when you had not even progressed the story of the game, or even moved to another area (never a problem in PnP, with a DM).
In some games, it was tempting to do this. If you just needed to "get that edge" you might be seduced into camping "just a few times", and you could rationalise that by thinking "well, I botched that quest back there", or something. But it can get out of hand and break the game...
As MazinKaesar alludes, DnD has a "challenge rating" for monsters, which is compared with the power-level of the party, yielding appropriate experience based on that (well, sometimes - it's pretty complicated).
I'm not really this oldskool, but I love the elegance of this style: minimal GFX, colour, anims - leaving stuff up to the imagination, BUT even moreso if it was "isometricised" (was that a contradiction?), tho' I doubt that would be possible on such a system...
Oh shut-up, oneshotdead!