Something I don't get, which may just be my own perspective getting in the way, is why rules-light games are perceived as "Cops & Robbers".A badly designed rules light game can, but nobody's defending badly designed games.
HeroQuest, Sorcerer, The Pool, Primetime Adventures, Dogs in the Vineyard, FATE -- one thing these games have in common is that any conflict at all that comes up can be resolved using the basic mechanic. These conflicts can be interesting and challenging. There's little cause for confusion or debate, except perhaps about difficulty levels (which always have to be decided).
There's also lots of things these games don't address. How much I can carry. Whether or not I can jump a seven-foot ditch. How long I can hold my breath. The relative damage of different-size swords.
But if those things ever came up in an interesting fashion, something involving a conflict with real stakes, you could use the rules to resolve them. And if they don't show up in an interesting fashion, then why do I care?
Similarly, on the topic of appeal to new players, I'm waiting to see more rules-light games that are actually written for them. I can't fault Everway for not producing massive of new roleplayers, because it's not easy for anyone to digest. How many games actually explain how to play? How to GM? I don't mean the usual five pages in the front and a chapter in the back of the GM Guide, but really explain it.
But look at Dogs in the Vineyard, and it explains what the game's about, how to make a character, and how to resolve conflicts. Then the GM's section explains how to create a scenario from scratch, specifically, in clear terms. I wouldn't give D&D 3.5 or Everway to a group who'd never played before, but if they were interesting in the setting for DitV, I think they could pick it up without help quite easily.