The way I see it is that when it comes to social interactions, online medium has become a tool for many to put out "words" and "fixed beliefs" rather than opinions or their personal genuine thoughts about a topic and why they feel so. Many that are shunned in regular social interaction done face to face, like how you mentioned in the start of the article, find it easy to leave their "words" in random places as they have more chances of being heard (doesn't matter if positive or negatively), without having any dire consequences.

Of course in the long run such comments will most probably be avoided, it still is something that doesn't bother the individual as it isn't worse than what happens on a regular basis. Like another comment said, comments are like a beginning weapon of an MMORPG here, and those using it in a bad way don't have any real intention of playing the game at all.

In the end, the only thing, in my opinion that will change the way things are is for people to be more open minded and a bit less selfish, understand the other person's point of view rather than force one's opinion on others, and try to play the devil's advocate in every situation to see how it turns out. That is, only if they intend to change in the first place.

Sorry for the long comment, reading the article just made me want to share what I felt.