One of the things I like most about CrossFit is how short, intense workouts with gymnastics, weightlifting, and bits of running/rowing create capacity to do SO many other activities and sports. CrossFit may not prepare you to win first place in a triathlon, but can easily complete one. It may not make you as strong as an elite powerlifter, but you'll be pretty strong! CrossFit will also give you strength and conditioning to ski, surf, play basketball, play football, swim, etc.

No other fitness program can claim to do this.

If you can spend twenty minutes doing pull ups, push ups and squats and get the same cardiovascular response as running a 5k, with all of the additional strength benefits of the gymnastics you're practicing, why wouldn't you want to kill two birds with one stone?

If you want to get the most benefits in the shortest amount of time, do CrossFit.