It's just not that big a deal. You shed your DNA everywhere. Knowing it isn't more useful than information about your life that is already collected and used to manipulate you all the time. It's one of the weaker forms of personal information available.
But pretty much any other use of a photo in a public place is fair game if it doesn't misrepresent you in some way.
"Doing bad things isn't a big deal because of all the other bad things already being done." is not a good justification:
Should an individual feel free to "dox" you with impunity because Google and Facebook have been doing it to you for years anyway?
"My DNA is my personally-identifying data," is a better one.
The question of what rights we have to our personally identifiable information is not yet answered fully, and the debate is an important one (e.g. consider GDPR and the "right to be forgotten").
Data's worth is recognized today by those who are harvesting it from us. The mountains of data which only a few multinational corporations can gather and store in globally-distributed data centers are imperative to machine learning and the artificial intelligences they are making, which will soon direct a great many of our daily conveniences at potentially great profit to them.
So it is important for us to today define what rights we demand to such a valuable resource, which is created solely by, and living within, the only item any of us has true natural possession of: our very bodies.
Do not forget that op argues it isn't that big of a deal.
>Data's worth is recognized today by those who are harvesting it from us.
There is a lot more case-based, abstract, and long-term worth to privacy that is often unrecognized.
I can’t take your hair off your head, but I can take it off the ground.
Somewhere, somewhen, there is likely to be another person who has a face, or fingerprints, or snippet of DNA that cannot be distinguished from yours within the accuracy of the tools we have today.