You say this like it's a "gotcha," but what exactly could somebody with no technical knowledge do about the microphone? If you're trying to say that if there were an equivalent to electrical tape but for the microphone, people wouldn't use it, then I don't even think you honestly believe that.

Also, it's bizarre that in a world that ratting has existed, you'd compare covering the camera on your laptop with a piece of electrical tape to paranoid schizophrenia.