> Just to give you an example, lookup the swissair in-flight entertainment fire incident. Tacking couple of screens and media server onto an existing plane should be fine right? turns out not really and 215 people paid the price of that decision with their lives.
I'm not super familiar with this one, but based on a quick skim of the TSB report (http://www.tsb.gc.ca/eng/rapports-reports/aviation/1998/a98h...) it looks like the issue here was not the IFE itself but a poor installation that significantly differed from the certified configuration and resulted in chafing on power wires.
It's also worth noting that this happened in the '90s when networked personal IFE systems were still in their infancy. It's 2021, there are no unsolved problems in installing a few cameras in an aircraft. A lot of them already have cameras accessible through the IFE, putting one more in the cockpit and a hardened DVR in the back isn't exactly rocket science.
Yes, aviation stuff often has a few zeroes added on to the price tag for good and bad reasons, but we're basically talking about a dashcam here. Low triple digit prices for non-aviation hardware, so even if you multiply the price times 100 it's still not really significant compared to the cost of an airliner.
There are no good technical reasons to not have video.