I think they were selling shovels during a gold rush.
With the popularity of YouTube growing, the demand from everyday people for better cameras and so-called "action cameras" increased significantly. It should have been pretty easy to see what would be profitable.
They were also taking advantage of the fact that most cameras are complicated, that most established camera manufacturers are slow to change and have a hard time valuing simplicity, and that the idea of an "action camera" was a new concept to average people. Having a relatively small product line also made it clear to people what they were about; it also made their products easily identifiable with their brand. Why buy an action camera from a company that makes a bunch of different things, when the action camera is what GoPro does?
To sum that up, I think they appeared on the scene at the right time and existing camera brands were too slow(at least for a while) and had poor marketing.
> 2. Where they have innovated, they've hugely missed the target. In particular, their drone release was just an awful, awful misjudgement.
Yeah, that seems like a huge misstep.