First of all, dangerous activities attract people, because it makes them feel relaxed. Dr. Alex Martin and his colleagues in University of Colorado hypothesized that performing or even watching exciting or dangerous activities secretes special chemical substances in body, which have a compensatory effect on the release of stress-related hormones. Moreover, all of us have encountered dangerous situations, which might be frightening, but remembering hazardous locations is desirable. (Why? Explain!)
Additionally, performing dangerous activities or sports could be considered as entertainment. One of the most important aspects of risky situations, which prevent life to be boring, is the sense of danger. Secure games or sports are not as attractive and interesting as risky ones. Today, most people have a monotonous rhythm of life. Scientists presume that all of us need unexpected occasions like taking part in dangerous sports in order to tolerate daily chores.
Undoubtedly, people practice new experiences through dangerous activities. For some people, reading the latest novel or attending international meetings is wonderful and is considered as a new experience. However, for others a new experience is one that is accompanied with a little risk. History has shown that nearly all the great who made deep changes in human life belonged to the latter category. As one may notice, famous scientists, artists, fighters, and politicians were naughty children who used to make a dangerous atmosphere and enjoyed it.
In brief, I surmise that people need changes in order to enjoy their life. They have to try in the hope that they find suitable activities to obtain this modification. Obviously, dangerous hobbies are a fantastic choice.