The recent Criticsm of Java Persistence thread on TheServerSide shows us once again that data access is still a very sensitive, emotional and almost religious topic.
I have said what I had to say in the thread itself, so no need to duplicate this here.
Many people have wrong ideas about persistence in general, and many people have their own views about how to manage it (while conversely very few people are publicly defending their opinion about how to manage pages in an operating system for instance). There is definitely something special about data access and persistence.
NB: I really think ODBMS vendors should stop communicating on the "the best mapping is no mapping" moto. First it is not true, and second it does not help them.