So in my opinion, people get into "religious wars" because the beliefs of other affect them.
Hell, when people get all worked up about a language there are benefits to convincing people to use their language -- better tool support, better libraries etc; and if they are on the losing side of a language they will have to learn another one.
In the end these types of debates are all about control, either direct or indirect. Direct -- Force, rule of law, etc ... Indirect -- public opinion, social mores, # of followers.