Passwords are unable to be shown in plain text in a spreadsheet due to security reasons. Basically, WishList Member doesn’t store the passwords and cannot retrieve them. Passwords are stored and encrypted using the WordPress password functionality.
That being said, there is an option in the Members > Export section of WishList Member named “Include Password (Encrypted)”
Passwords will be encrypted and included in the export but they will be shown as random characters in the exported file.
If you Export members and use the “Include Password (Encrypted)” option, you’ll be able to export a list of members and then you can import that list of members to another WishList Member powered site. Those members will retain their passwords and the passwords will not be visible during the process.
More information on Exporting Members can be found in the Export Members Knowledge Base article.