I suspect because private insurers force so many people to change doctors every time their employment circumstances change.

http://www.pnhp.org/news/2005/november/int...


The US leads the world in medical error rates because private for profit insurance fragments the provider pool and forces people to change doctors all the time whenever their employment circumstances change. It doesn't matter how good Obama's electronic records system turns out to be--it can't replace a provider who has known you for a long time.