23andme requires a warrant. They publish a transparency report and since 2015 they've gotten a grand total of 7.
Having said that, if my DNA catches a distant relative who commits severe crimes, that hardly discourages me.
As an aside, what's with the bizarre moderation of HN lately? The circle of users allowed to downvote has gotten perhaps a little too big as the utilization for noting "this does not conform with my biases" has turned absolutely Reddit-like.
The parent post is wrong about 23andme -- it doesn't matter if you like the company or not, their point is wrong -- and the notion that you're caught up in a "dragnet" because of a far off ancestor committed a crime implies that you think the people who do genetic ancestry are idiots.
This confusion matters if the average customer is making decisions based on that info. It doesn't matter (yet?) that they require a warrant and are transparent. All that matters is that enough people believe 23andme will share personal data for sales to be affected
However I doubt that angle has any relevance to their sales decline, beyond the most fringe element. As others have rightly said, the majority of people who have an interest in the information that 23andme offers have already done it or a competitor, having probably picked it up over one of the multiple Prime Days, etc. They do have revisions of their chip and improved information, but thus far they haven't marketed that for repurchases.
I've seen anonymous but redacted proof-bearing confessions from people these companies saying they "fuck with pure white people" by throwing in random ethnicities, so...at minimum, not all of them respect the integrity of their work.
Which shouldn't surprise anyone, due to...them being humans.