I think a lot of the antagonism you see from certain open source communities comes from Twitter nowadays. (That is, angry debates exist everywhere, but it leaks out of Twitter better than someone going crazy in an IRC channel.)

Ten years ago, you had to write a blog post and hit publish.. and that gave you a chance to reflect and retract. But now you can tap out a gut reaction to the latest drama and keep the feedback loop going.

This is all just based on personal observation and therefore unscientific, but I suspect most communities have similar levels of antagonism between members and topics up for internal conflict. Those communities whose members are communicating more on Twitter, however, have dramas that rumble on for longer and get more external coverage than those sheltered away on private mailing lists and IRC channels.