I don't think Emma ever said it was her "dream" to build an eco-friendly clothing empire, so the Daily Mail article is somewhat hyperbole (not as bad as some of xxS's hyperbole).
Emma said in an interview she would work for free for any organic, fair trade clothing company. This was no doubt at least partly for her image. Emma did her part. She went to Bangladesh with Safia Minney. No one would have heard of People Tree at all if it were not for Emma. She didn't get paid for any of it. It's not her fault the stuff isn't selling well.
Also, Echee claims that Emma never wears organic clothing. Maybe she didn't were People Tree clothes on red carpet events, but so what? Do they even make expensive gowns and stuff?
We only get to see a small fragment of Emma's life. It is possible that Emma wears more organic clothing than Echee's thinks. We only see her maybe less than one percent of the totality of her life. This is not enough of a sample set to draw conclusions from.