I am actually more shocked that you are shocked at those comments.
At the risk of stating the overly obvious, this is the age of the internet, where everyone is an expert and everyone has a valid and factual opinion (doesn't that last part just send your mind into a logic finding tizzy?)
I ran a club and associated online messageboard for nearly a decade and what I came to find out is having such a gathering can be a very dangerous experiment as people who don't see each other face to face have NO concept that the person behind the keyboard on the other end is a human being and as such does not need to be given the most basic of respect and consideration.
I guarantee you, face to face there would only remain a VERY small percentage of folks making comments like that to your or my face.
Add to that the constant one-upmanship of whom can provide the worst insult and there you have it, pack mentality at it's finest with the amount of people participating inversely proportionate to the intelligence of the conversation.