The passwords that are the safest are random long ones, generated by a computer.
But those are generally the ones that staff complain about the most, because without a password manager, they are tedious to use let alone remember.
A weak password leaves your business wide open to hackers! They can easily crack obvious short passwords using a brute force process (essentially just keeps guessing until they crack it and this is automated by a tool).
This video will take a look at the risks of using weak passwords.