Why it's grown quiet here is a very good question.
It grew quiet before Seth passed away, so that isn't the reason. Though, no doubt it's a contributor.
I certainly don't know. I can make up insta-theories with the best of them, but they aren't worth much.
My guess would be that after the first round of interest, book's original publication, the era of peak blogging etc. ... well for some reason new people didn't join the community. The old people wandered off as they met their goals, or it didn't work out for them. (I've been using it off an on since the original article and it's still working fine, but there is only so much you can say about it
It clearly worked extremely well for lots of people. You'd think word of mouth would have kept is vibrant. Maybe it's so odd, and people are so cynical about diets (not without reason!) that the word of mouth dies out for that reason. I can't say that I've _every_ explained to anybody and had them go on to try it. Inspite of the clear evidence, which is usually why they ask, that I have lost a huge amount of weight using this approach.