I think it's kind of like the difference between e-sports and real sports. Real sports and e-sports share their competitive nature, but real sports have the endorphins that balance that out with positivity. Online discussion can be antagonistic just like real discussion, but real discussion often has non-verbal cues, food, relaxing atmosphere, small talk, jokes, etc. that balance that out.
Not any more than in days past. People just don't deal with it well anymore.
Possibly because they missed out on three formerly common phrases when they were growing up: "Too bad," "Who Cares?" and "Get over it."