The default WordPress themes display all first level pages by default. When importing a GEDCOM file, hundreds of pages can be created, all first level pages. The intent of assigning a Parent Page is to push persona pages down to a second level, allowing an admin to manage the display of those pages.
I can not tell you how many new users have skipped the step of assigning the parent page, then emailed me to say that rootpersona has destroyed their site. (Picture a front page with 100 or more entries in the menu bar).
rootspersona will now create and assign a Parent Page by default. The parent page is NOT meant for display, as the menu is very large on most sites..