I don't think there are easy answers here, but it's a conversation we should be having.
If you give anyone (say, PayPal) your address, you’ve given then your roommates’ address as well - since you share the same IP. Nobody cares, even though the third party can immediately begin identifying your roommates without harvesting their DNA, like they would in the case of 23andme.
There’s a slight difference.
I suspect you’re attacking a strawman.
Edit:
Or, by the same token: a parent is liable for diluting the value of their siblings DNA because they passed that DNA on to children. I don't see this going anywhere.
It's like sharing your private key, knowing that others also use that private key.
You immediately make a large portion of your family tree discoverable.
It's the same underlying reason that we (most of us lol) treat revenge porn as a bad thing. You take someone else's blanket of privacy away without their consent.