I couldn't disagree more. Knowing more about your body is always a good thing -- the fact that many people won't know what to do with that information is inconsequential. It may not make sense for many (most) people to buy into 23andMe, there are a lot of people out there that can understand this, or at least find it interesting to be able to peer into their genetic makeup.
Surely if the average person is told "There's an X chance you'll die. There's a Y chance you'll lose a leg. There's a Z chance you'll be blown up", they'll worry unduly no matter what X,Y,Z are.
I can see what you're saying, that if you're a qualified doctor, or have studied medicine for years, then 23andme could be useful, but for everyone else, I think it could be very dangerous.