Advanced Export/Import (WordPress) Object Users: Make a full user backup, restore wherever you want!
It's too simple to do what the plugin does... However, have you got a question? Please ask us on forum.
This is because the importer does not keep any information about the field except than Field Name, Field Group and Field Value. Any other information is left behind. So the better way to make an import that grant the exact structure for xprofile field is to create the XProfile Fields on the new WordPress instance before the import is done then make the import.
If you have imported the password field too then It was changed and you have to ensure that the same secret key is used in both old and new wordpress.