Bedrockgames
I post in the voice of Christopher Walken
I agree with @Fenris-77 that rules light isn't contrary to consistency. I do think for many of us who like Rules Light, consistency is less of a priority. I want consistency of setting, of the player's ability to feel like they are there. But that doesn't mean I need to create a new house rule every time I rule on an action, or that I need a unified mechanic undergirding every potential action. As long as I have tools to draw on to make my rulings for what feels most appropriate to that moment, that is good with me. I do play rules heavy too and I do think there most players I meet who like that, enjoy having all the mechanics clearly laid out in the advance for any potential action. Theoretically you can do that with light (i.e. roll a d6 every time you want to do anything), but I think they also want varied mechanics handling discrete areas of the game (it can be like d20 with a core d20 roll, but they want individual break downs of skills, abilities, etc). I do think it is hard to come up with a set of core principles though underlying all this. Some rules heavy players I know, want something that simulates the world, some want a game that lends itself to tactics, some like crunch for its own sake.