The more info link shows in the the photo column for a member, so you have to enable the option to show photos in the directory. If you don’t set a featured image for that member, then just the more info link will show in that column. If there is an image, then the image is linked to the individual post page (more info link will still show below the photo as well).
Also, it’s a “smart” link. If you don’t type in any info in the regular post content area for a member, then the more info link will NOT show up (since there is no more info to show other than the name).
Perhaps I need to modify the help content to make that more clear?