From your own link about 23and me - it says the opposite:
23andMe
requires a valid legal process to consider producing information about our customers. Law enforcement agencies should read 23andMe's
Guide for Law Enforcement document prior to contacting 23andMe.
A subpoena is a valid legal document. And 23andme HAS responded - not sure why you're saying they haven't. Again, from your link:
In certain circumstances, however, 23andMe may be required by law to comply with a valid court order, subpoena, or search warrant for genetic or personal information.
Look up the Helen Prusynski case (40 year old cold murder case solved with 23andme data after a subpoena).
But there's a way to do it without subpoena if there's a firm suspect and all that's needed to seal the deal to get an arrest warrant. And that's to go to a relative of the suspect - perhaps distant - and get them to submit to Ancestry and 23andme, and then share his/her results - then use a genealogist to give LE the names of all of that ancestor's descendants. That's resulted in quite a few convictions.
Getting someone to do this isn't as hard as you might think (often the perp has strained relationships with relatives or they may already be living in fear from knowing him/her).
I believe a subpoena for both Ancestry and 23 was used for the Norcal rapist - took 10 days to figure out who he was.
And of course, there's always GEDMatch. But Ancestry and 23 do not refuse to obey a court order (subpoena) in my understanding and that's what they say right on their websites.
23andme requires proper legal service of the subpoena and does not respond to certain international requests. If the Justice Dept files the confidentiality form (regarding notifying the person whose DNA provides the hit), 23andme will obey what the court decides on the issue.