The premise of the article is a fallacy of equivocation over the word "nothing".
"I have nothing to hide" is used as an argument meaning "I have nothing to hide for which I might be wanted by the authorities"; it does not literally mean "nothing at all".
"I have nothing to hide" is an argument used against the advocacy of tools for anonymity and cryptography, and in particular tools that use strong cryptography and are free of back doors.
The counter argument "you have your personal privacy to hide" to hide makes a strawman out of "I have nothing to hide" around the interpretation of the word "nothing".
The nothing-to-hide argument, in its strongest form, is specifically limited as an argument against the advocacy of tools that make governments nervous, not against fig leaves and coconuts. That part of it is plausible, in fact: basic privacy arguably does not need strong anonymity and crypto tools that are free of back doors.
You can be investigated by a government in ways that actually "respect" your privacy, so to speak. By this I mean that they get into into your accounts (using exploits or deliberately planted back doors), don't find what they're looking for, and then move on. Nothing private of yours has become public, and you don't even know.
I'm not saying I agree with any of this, just that you have to take the "I have nothing to hide" argument more seriously: the taunt "so open your e-mail to everyone" is not really an effective response.
Those who use the "I have nothing to hide" argument are statists and conformists; they really mean "I am willing to open all aspects of my life to the authorities in cooperation with any investigation", not "I'm willing to open my life to the public". (The tacit implication is "those who are not willing to unconditionally cooperate with the authorities to the extent that I am are not merely advocates of liberty: they likely have something to hide, whether it be links to terrorist organizations, child porn, or evidence of crime. Unlike me, the advocates of those tools and systems are not so confident that nothing will be found.")