They have their uses
I had cameras on my bike when I commuted daily to the City and back and they came in handy more often than you would have thought and not just in relation to road users. People act differently when they think that their words are being recorded, they are fair less tempted to cut corners, exaggerate or fob you off.
There are times and places where such monitoring is unsuitable but don't write off the tech because of a couple of edge cases.