For entity beans removal, the client/another bean would usually invoke the remove(Object pk) method. The primary key of an entity bean can be obtained easily via the getPrimaryKey method.
Since session beans & MDB do not have any primary keys, the remove(Object pk) method obviously won't work. So another remove(Handle h) method was needed.
EJBObject -> remove()
One of the reason that this remove method exists is that local session beans & local MDB do not have handles, that means we cannot use remove(Object pk) & remove(Handle h). If the remove method wasn't provided, they would be no way we could remove these beans!