> Because insurances can use DNA knowledge as a justification for charging you more
In America they cannot. This is forbidden by law.
... But they should be allowed to, you are more risky to insure. Just like under 25-yo's are more prone to accidents; or coastal houses are more prone to flooding.
If having the wrong IP address costs $1k extra per month, but only of other people know, then you'd also be more careful about keeping it a secret.