If you think about it, Strava is like the Guinness Book of Records writ small.
This exact analogy occurred to me last night. Strava, like Guinness, publishes the athletic (and other) achievements of persons around the globe. But in the case of Guinness, they determine the categories, e.g. fastest speed ever on a downhill bike. In contrast, it is Strava's users who determine the categories (in this case, segments) and then the user base goes about seeing how they fare in those categories/segments. Strava is not creating dangerous categories/segments, its users are. Moreover, if the user base views a created category/segment as dangerous, Strava includes functionality to allow the user base to determine this. Finally, Strava allows its users to hide segments, so if you don't want to see categories/segments that you individually seem "dangerous" or otherwise undesirable, then you are free to hide them.
Strava is just like Guinness in that it provides information to its users, who may or may not be inspired to act by such information. But unlike Guinness, it allows its user base to 100% control and determine what information it provides, and allows both the community and individual users to control what information is presented to them.
The email notifications (that you have lost your KOM) have some people seeing red, but let me ask you, if I go mountain biking with my buddy on a Sunday, send him an email on Monday ribbing him about how he needs to get his arse in shape after I dropped him on the last downhill, and on Tuesday he goes out and rides that same trail beyond his ability and tragically dies, should I be sued by the family for causing his death? I sure hope not. And while the email notifications may be playfully worded, they are essentially just another form of information sharing, which is the entire premise of Strava.