I dislike the way the article uses the word "violence". Nothing that happens on Twitter is violent. The definition of violence right from a Google search for "define:violence" is
behavior involving physical force intended to hurt, damage, or kill someone or something
Nonetheless, the author articulates the reasons I do not use Twitter myself. The amount of drama that site creates seems, to a non-user, to be far in excess of the amount of insight it generates. I have never heard of a really great conversation or unique, insightful idea emerging on Twitter. I have heard, a lot, about idiotic fights that escalate into real world problems. I agree that the 140 character limit is the cause of such problems.