Desdichado
Hero
I think there's some problems with your assumptions. I'm not sure that I'd agree with the notion that the BECMI line was "simple" to AD&D's "complex"; as the systems evolved, they had similar levels of complexity, although they didn't manifest in exactly the same way.
Similarly, the 3e/Pathfinder model is, in many ways, complex, but in others was remarkable for it's streamlining and consolidating of mechanics to an integrated "core" mechanic, at least relative to what D&D was doing prior to 3e.
And furthermore, I don't know that the divide between 3e/Pathfinder and 4e fans maps well to the divide between rules lite and rules heavy fans.
Similarly, the 3e/Pathfinder model is, in many ways, complex, but in others was remarkable for it's streamlining and consolidating of mechanics to an integrated "core" mechanic, at least relative to what D&D was doing prior to 3e.
And furthermore, I don't know that the divide between 3e/Pathfinder and 4e fans maps well to the divide between rules lite and rules heavy fans.