While most programs are happy to stimulate only the musculoskeletal system and its components, we find these programs lacking and have discovered additional ways to increase the effectiveness and efficiency of our programming.
There are many proven benefits to shaking up the body a little. By "shaking up" we are talking about getting upside-down and weightless for a moment. These additional benefits include: improved balance, improved proprioception (spatial awareness) and improved coordination. Dramatic movement of the body is also thought to be responsible for improving: flow of the lymphatic system (disease prevention), cardiovascular circulation, and digestion.
There can be no doubt that there is HUGE entertainment value in watching a full-grown adult, who hasn't done a cartwheel 20 years, attempting a cartwheel. It's just FRICKIN cool.
But that isn't what GPP is about. Remember, our mandate is - " MAXIMUM EFFECTIVENESS and EFFICIENCY." We will only do what is ABSOLUTELY necessary to improve health. We are willing to do WHATEVER it takes to make this happen and we realize it can (probably will) be HELL. But, we are unwilling to do even ONE more rep, of ONE more set than is needful.
Cartwheels just happen to be dang good exercise. They have benefit that would be hard to gain outside of other movements like them. They do things for your core that would be hard to simulate. They are also pretty fun and...the entertainment value alone makes them worth programming.