The problem with the hobbyist approach (and this is coming from someone who owns multiple Raspberry Pis) is that you most hobbyist don't really have the resources to tackle every engineering aspect of building a reliable camera. We have people dedicated to fine tuning the WiFi drivers in the device, writing scalable and secure video storage/streaming services, figuring out the thermal profile of every component in the cameras, minimizing noise in the camera CMOS and the WiFi antennas, making embedded software that will reliably reboot itself after a catastrophic crash... etc, etc, etc.

Don't get me wrong, every one of those aspects is a lot of fun to tackle on your own, but ultimately would you trust your home to something you can throw together in a few weekends? After seeing the amount of work these guys put, I probably wouldn't.