Now compare the cost of hacking into a database to the cost of obtaining millions of genomes by physically taking genetic material and then sequencing it. Then consider that your DNA is yours for the rest of your life.
Simply because data can be obtained by some means does not make protecting that data useless.
As the value of DNA increases, people will collect it. Restaurants, washrooms, your employer, airlines, Uber etc. all could have trivially easy access to your DNA if they choose to.
Just because there is 'trivial' access to certain attributes of people doesn't mean that it's legal to capture those attributes, and even if you do capture them, they're worthless on the legal market. E.g. see SF ban on facial recognition.
And that's only if such legal barriers are even constructed which I'm not sure they will be. Look how the privacy battle has turned out thus far.
Trying to keep genetic identity anonymous is security through obscurity. You have shed thousands of skin cells in the time it took for you to read this. If people want your DNA it's trivial to collect -- and will only get easier and more common.
A better use of our time is to address the ramifications of public DNA and prevent it from being misused.