If Combat Is Not The Main Focus
I rarely get involved in games that are focused on combat situations, and even when I do, I tend to take non-traditional approaches to combat, so that the typical combat rules often require a little tweaking. As such, I tend to prefer games that have a fairly simple combat system in the first place...if the GM is already going to have to make judgment calls on what I'm trying to do, I figure there's no sense worrying about a rules-laden combat system (it's not that I set out to find loopholes in the rules...I just get ideas and find the GM is often responding with, "Well...the rules don't really cover that...but roll this and this and we'll see if it works," or something similar. My personal favorite system for gaming was (and is) the D6 system used by West End Games for their Star Wars RPG, to give you some idea.
That being said, you can oversimplify combat, which takes some of the tension out of it. It needs to be a risky proposition, and even in systems which are designed to basically require a player to deliberately attempt to be killed in order for a character to die, there's still a lot of risk as far as debilitating injury, unconsciousness, extensive recovery time, etc (at least, in my experience).
As stated by numerous people earlier, it depends on the focus of the game. If you're going for a hyper-simplified combat system, that should be communicated to the players before the game starts (and I'd go so far as to say it should be part of the game information addressed in the RTJ information thread). But if everyone's on board with the idea, there's no reason combat needs to be complex...I don't know that I'd boil it down as far as the results of a single d6 roll, but I do appreciate the random variations that can come into a game with some dice being rolled...