It isn't just common among younger folks, but those in my age and older. I am in my early 40s and some of those people are not only older but work in InfoSec!
Let that sink in.
The real danger of the "I have nothing to hide" response is time. *Right now* you may not have anything to hide, but since the #american people decided to re-elect a criminal #fascist with a penchant for authoritarianism, that may change. And then you WILL have something to hide!