Does one not think that there could have been a better way to encourage people to lose weight than to laugh at them, ridicule them and, to be honest, hate them? I'm not so sure if I consider your analysis to be a valid representation of the intentions of the people there, though I have little experience with the community itself, this model of "helping" people seems very alien to me, and contrary to what I had (intellecutally) understood to be how people behave on the Internet.

I think also ultimately it is the choice of the person to find their encouragement, as much as it is very difficult. Diet communities are built around the idea of individual desire to improve (which is why posts like "Three weeks in and it's great!" get upvoted there) rather than having it 'forced' upon them.