In my opinion, it is something unnecessary. Indeed, if surveillance tech is so cheap, why not point the cameras all around the aircraft so crew can actually see what's going on outside. As for safeguarding data; I am sure the bigger countries with some decency, expertise and strong unions will never have a leak. My problem is the smaller countries with weak unions.
Look for an example once at the crash of the Luxair Fokker 50, where in the preliminary report the full transcript of the CVR was published. Meaning, the CVR transcript was out in the open, and the crew was already convicted by public opinion before the official report was out. Purely because some of the people involved in the investigation had no idea about good practice or privacy laws.
Now with videos it will go the same way, and I really would not want anyones family see a relative die in the cockpit.
Now on another note: Terrorists caused more deaths in recent years, why not put a camera on each seat row in the cabin?
I think its just some sick desire of voyeurism, that's all.
Let all these people think of a solution for Zimbabwe instead where thousands of people die each year because of violence and an oppressive regime.