I stay away from forums where people give free reign to their nastiness. On diet related forums if your intent is to help other people become healthy or convince them that your way is the most beneficial then it is best to refrain from nastiness. It tends to alienate people not bring them into the fold. If your intent is to demonstrate your superiority then that's a different story and nastiness does a very good job of demonstrating to others that you believe that you are superior.

There are certainly people on this forum whose attitude gets in the way of their success and instead of looking inward to try to figure out how they can change themselves they look outward and blame the diet or blame their circumstances or blame something that is external to themselves. I too find this way of looking at things frustrating. Sometimes I won't respond because I am afraid that my frustration will get in the way of my saying anything that might be helpful. Other times I try to think of a way to phrase things that the other person might be able to hear and might help them turn things around.

I think it often comes down to whether your intention is to show that you are a superior being or if your intention is to be truly helpful.

Jean