"the service can't use its genetic testing to give you a heads-up about upcoming disease in your physiology, which is one of the big sells of 23andMe"

Nonsense - I have a common variant of one blood clotting factor known to be responsible for a greatly increased risk of deep vein thrombosis and life threatening pulmonary embolisms. My mother has the same autosomal dominant gene.

She was hospitalized for DVT and PE following a knee surgery, was genetically tested and found positive.

23andme identified me as being a carrier of said mutation and followup genetic sequencing confirmed the diagnosis.

Now I know, with certainty, that I must periodically get up and move around during long car rides and plain flights or risk a life threatening event.

Health-related discoveries aside, there are countless things to be analyzed from 23andme data, including ancestry and data mining for correlation with biometrics (imagine being able to reconstruct facial images based on dna samples alone).

There are always hypercritical crankpots to speak out against any new technology. If only these people would imagine constructive ways to make use of this so-called "useless" data.

Innovate people.