Having engaged in the past in some of those conversations, I find that for the most part, the bringers of woe reject rules-lite systems out-of-hand. They would rather criticize them based on their understanding of what they think they are than spend a day trying it, when that actual play would answer their theoretical criticisms.
I think that rules lite systems are hard for people that are used to more crunchy systems to grasp without playing them. I think it is similar to what happened when I bought the Amber Diceless Roleplaying Game, and because I was so used to using dice I couldn't grasp what it was doing with the resolution system (as easy as it was!) until I finally just sat down and ran it.