This is an empirical claim, and there's a wide range of RPGs against which we can test it. And the outcomes of that test will probably be different for different testers, who have different preferences.
For my own part, I think active defence is interesting in a system like Rolemaster or HARP (where you allocate attack and parry each round from a common pool) but less interesting in Runequest (where each PC has a fixed attack percentage and a fixed parry percentage). 4e has persuaded me that PCs being hit is often more interesting than PCs being constantly missed, because a result of being hit is movement, conditions etc which change or raise the stakes. But a system whose dynamics rely on the PCs being hit will probably need in-combat healing (as 4e generally does).
In my view, the big problem with attrition as the stakes of combat is that (i) it is boring until the last fight is actually taking place, and (ii) it can fail to generate the requisite stakes if the players get to decide whether or not their PCs engage in any given combat.
I can think of at least one way to reconcile no in-combat healing with dynamic combat - design a system in which NPCs, monsters and PCs have a reason to use (non-damaging) pushes, grapples etc instead of damaging attacks. (Burning Wheel has a degree of this to its combat system.) But that would be something of a change to D&D combat.