Your post very much reminds me of the usual atmosphere in slashdot-like discussion forums (for Germans e.g. the comments at heise.de), and of course some newsgroups.
It seems that we have developed a culture where it is of the utmost importance to convice others that you are right, and to utterly eradicate anything that seems wrong to you. I can see it in religious flamewars (x vs. y), which for me embody the very definition of "religious". I can see it in phenomenons like "...she's a flight risk.": If you don't believe it, you can just treat it as a nice story. However, many people opt to bash anyone that "believes this bullshit" and "lies to me". Why? I am shocked at how much time people are willing to spend to abuse others and to defend their own opinions. I don't get what kind of benefit this is going to give you. There is so much bullshit in the world, you can't fight all of it.
Curiously enough, I have been tempted to jump in myself a few times when someone posted blatant bullshit and I knew the facts to be very different. But I found a trick that so far worked for me in 100% of these temptations: I go away and do something different. After five minutes, I find it's not worth posting anymore. Neither the original post, nor my reply, are going to change the world. Shutting of the computer and making pancakes will, though. Or at least they will taste nice.