Lively, vigorous argument is a good thing in itself, and won't drive away anyone who's worth keeping. We're not a social club here, we're producing a product, and if a little shouting helps that project, that's fine. What drives people away is when they feel they aren't contributing. If they spend more time arguing than writing, and the arguments don't actually serve to improve the articles, then they feel their time is being wasted.
So arguments here should be judged not on their belligerence, but on their productivity. Is the argument truly seeking to make a better article, or is it just arguing for the sake of argument, or to push an agenda?