I think Reddit is a good explanation of the internet. One moment you might be talking to the nicest people to exist online, the next you could find someone who wants to ruin your day simply because it's Tuesday.
Reddit has so many people with different interests and views that I think they just end up colliding a lot, which can of course cause friction.
It also depends on that day they're having - have you ever felt like you've been far too unreasonable/rude or oddly nice? Humans are fickle creatures when it comes to emotions. Sometimes I feel like I want to hug everyone I meet, other times I just shout.
In the end, I think that's all it really is - Reddit has so many different people, it's hard to nail it down to one thing, you know? Guess that's what makes Reddit special.
"NintenDON'T sue me please haha"