The key to whether something represents courage or not, and whether it is a positive and constructive activity, lays in your motivation for doing so. Often times the person who has to be the toughest guy in town, or who is always the first to take on a dangerous dare, is in fact the most insecure. He or she constantly tries to prove to themselves and to others that he or she is not a coward. Often, the person who places a disproportionate value on winning that match or doing the most death defying dare has a core of insecurity. Their life is a constant battle in which they attempt to prove to themselves and others that they are not cowards.
Some people never learn.
Through convincing others, they hope to convince themselves. There are always that insecure few that insist that they have all of the answers and that everyone else is either incompetent or incorrect. You don't have to look far to find this insecure behavior in the martial arts community. You would think and hope that martial arts would be the last place that you would find this behavior, but unfortunately, it is frequently found. Ultimately, however, people like this are usually viewed as troublemakers in the end.