A lot of people love to stir up debate and have arguments. One of the best ways to initiate one is by asking religious and political questions that "choose a side" on an issue.
It's an invitation to solicit opposing views for the sake of argument.
At the end of the day it's a waste of time and energy to get all "fired up" because most people have already made up their minds that they're right! Our ego also keeps us from being "open" to other views.
Nevertheless some folks find it impossible to resist commenting on questions regarding topics when they strongly oppose the questioner's slant. (Politics, abortion, same sex marriage, Christianity, pre-marital sex, adultery, and immigration). Hot topics!
However it's one thing to have an heated debate on these topics and another thing to resort to "personal" attacks and insults simply because one disagrees with another on (one) topic. It's ugly to see adults resort to name calling.
Sometimes it's just best to (agree to disagree) and move on.
It's highly unlikely that anyone will ever change another's mind in the heat of battle. For some people there always has to be a "right" and "wrong" or a "winner" and "loser" in any disagreement. They can't simply (agree to disagree) and move on.