Yes, because rainbow table attacks are still surprisingly effective. Although what is even more surprising is finding password still stored in plain text somewhere.
If the password complexity is small, than sure, you can use rainbow tables. But if the password get longer and longer, than have do you want to store the rainbow tables? Also if you have salted passwords, how are the rainbow tables going to help?
Which is why there are Identity and Access Management (IAM) and Privileged Account Management (PAM) solutions that help protect against a users own laziness.