I’ve forgotten the details now, but one thing was the naming. For example, who can guess what a “display group” is without looking it up? (Does it involve displaying things? A group of what?) Even the name “Enterprise Objects”, why should a database framework only be useful to enterprises?
I remember preferring Hibernate when I encountered it although I agree that’s far from ideal either and there’s plenty to justifiably complain about there.
EJB Entity Beans were definitely worse than either, not supporting any kind of inheritance modeling, requiring altering many different files for a simple change like adding a field.