Recording yourself doing sport only makes sense if you are really good!
It's like any other complex tool, garbage in garbage out.
Check out on the roofs, the guys who break into sky scraper construction sites and scale the buildings. Go Pros work perfectly for their use case:
Then, I started mounting it to my dirt bike helmet, just for video evidence if I were to wreck and die. What I didn't realize was just how painfully slow it feels to watch a video of me (barely an amateur rider) on a track. The silver lining being, watching that video has helped me improve quite a bit.
My problem with GoPro was that it became apparent that they relied on a yearly upgrade cycle. I'm willing to do that for an iPhone that I use daily, but not a camera that I use a few weekends a year. After they released a 1080p camera and the remote that let you operate the camera without constantly removing your helmet, I stopped upgrading. I occasionally watch their product launch videos but I just don't want to spend any more on this product space. I think the image stabilization has potential, but the 3D / 360' camera is a gimmick until there are better ways to consume and edit that content.
Another big problem out on the slopes is that phone batteries drain quickly in the cold and operating phones with gloves on is still a chore. Any app-based improvements that GoPro has introduced feel like a non-starter to me in many of the environments that GoPro is useful.
My GoPro videos are wipeout compilations, action packed and fun to watch.