A lot of new comers don't lurk first, or follow the rules. They also seem to be 13 year olds a lot of the time, or at least act like them. Also, when people don't lurk first they tend to post threads that we've 20 times already, which turns it into automatic flamebait because it's just annoying.
And lastly (but I'm sure there's more) they get so defensive about everything, if someone's being stupidly offensive just ignore it and move on, and if you're wrong just admit it.