Mountain bikers becoming injured isn't a question of IF, but WHEN.
If you have a coworker in their 30s or 40s who is just starting to get into mountain biking (a common midlife crisis hobby), expect them to have a MTB related injury within the next year.
Damn I hit 30 this year and planned to buy one.
Mountain Biking just seems dangerous in general. I do a lot of trail running, and at this point I feel like my most likely source of injury is from a mountain biker colliding with me.