That manifesto I just read there was pretty scary and cult-like, complete with totally off-topic jabs at socialism and uh, science?.
I'm having a hard time reconciling that with what my wife and I have experienced at our local Crossfit gym, which has been among the most supportive and pressure-free experiences I've ever had in my life.
To be honest, nobody's ever even mentioned diet to me there and I'm pretty overweight. The Crossfit diet seems to be low-carb, high-protein, high-vegetable which frankly is very sensible and not exactly extreme.
One thing I'd been warned about before doing Crossfit was that they don't always teach proper form for weighted exercises and that therefore there's an injury risk. I've been very wary about that. But the instructors at my gym are super responsive and proactive when it comes to my form. High marks there.
As others have said, Crossfit gyms are independently operated. Culture is going to vary by gym. I suspect (like anything else) the gyms that garner the most attention are the ones that are kinda on the fringe and not the majority where you go do fun/grueling workouts with a supportive community.