I will agree with the cultish aspect of it... but even the people who created it, it's not how they live their lives on a day-to-day basis... it's more of a way to get yourself ready for a cleaner eating lifestyle. The support they offer is nice though. It's kind of that tough love approach that I think works well for most people. And with the inflammation, they explain how it affects certain aspects of your health, and you know what, I'm sure some isn't going to kill you either.
I think it's more a way of trying to differentiate between being healthy and trying to lose weight. For optimum health, I guess you'd want your body to absorb all of the nutrients that are in food with the least amount of side affects. So in that light, the no grain aspect of it would mean you're more healthy than if you do eat it. But like you said, having some inflammation isn't goign to kill anyone. For me, and I'm a pretty big guy, when I have done a Whole30 program, by the time the 30 days was up, there was a noticable difference in the size of my gut because I was a horrible eater prior to doing it. Pasta a couple times a week, a sandwich or two a day, etc. So obvioulsy, I was going to see more results than the person who goes out and has a slice of pizza on the run, but eats a salad with lean protein everyday for lunch.
To each his own. As long as people are eating in a way that makes them happy and not super unhealthy, do it up. If you want to eat 100% organic, by all means do so.
Hope you all enjoy the long weekend.