Banks are not owned by the costumers, but the Union is.
Step-by-step explanation:
The main difference between the two phenomenons is simply that the Bank is run by someone who is separate from the costumer base of the bank itself.
It is run by people who have no stakes in the interests rates other than profit from the costumer.
The credit Union is much more liberal in that it is the members who have a stake in maintaining good business and lending practices because they are the ones benefiting from the good practices.