I'm not a conspiracy theorist, But I think the protection mechanism is just a waste of space Don't get me wrong, I do replace diodes and caps every time, but I need to watch a debate about the whole thing
They have those on CB's. What they do is if somehow someone powers it up with the power reversed, it shorts the reverse power to ground. Often, like in the vid above, the protection diodes short after this and need replacing. However, if those protection diodes where not in the circuit, and somehow the device got powered in reverse, it would usually take out many of the circuits in the device. Hence, safety device blows and needs replace, or no safety device so the whole device is now toast.