It's not hard for anyone to understand. If you're worried that the OS is hijacking your camera, why would you stop being worried just because you're using the camera.
Your argument seems similar to "why would you care about a microphone spying on you 24/7 if you're willing to sometimes have conversations that might be overheard?"
Yes obviously when you use your webcam you're aware that it's not impossible you're being spied on, and some people may choose to never have a webcam for that reason. For those of us who are happy to take that risk for video calls, we don't have to also accept that we can be spied on any time the laptop is open.
I don't care who watches me through my camera, I was just trying to point out that people aren't stupid about the hardware switch. Some just find it ironic that there is a hardware shut off for a camera on a computer operated by Google.
I think regardless of the fact that it is technically possible with any hardware and any operating system, it is difficult to argue that the risk is the same on Linux as it is on windows or ChromeOS.
I doubt ChromeOS or windows are spying on you through your camera either when you are or are not using it, but people can be sure their Linux distro isn't.