Agreed. You never see a video game where an incremental power increase is random and "locked in", unless the entire game is designed around that purpose (like a hardcore mode or a Rogue-like). ['/QUOTE]That's just it, though: in many ways D&D
is a Rogue-like!
The only difference being that you don't (usually) have to restart the whole game/story when you die.
Any system with escalating challenges requires a high degree of predictability, or at least knowing how much and which systems should have random elements. You are playing with fire if "staying power" (health/hit points) is one of the systems you choose.
You would also be hard-pressed to find a large audience for your game. That much swinginess isn't fun.
Oh, I don't know about that - D&D seems to have survived well enough with it for the several decades prior to 4e.