It seems like similar thing as in Poland, where traditionally name Maria, so the polish variation on name Mary, wasn’t allowed to be used by for instance polish queens (when Marie Louise Gonzaga was crowned polish queen she was forced to get rid of the “Marie” part and keep only Louise, but there were also other examples). It was also because of the religious/cultural reasons, mostly because the catholic church in Poland believed that it’s not proper to name a sinner the name of Mary the Virgin. Because of that there’s a lot of variations on the name Mary in polish folk culture, as to avoid these restrictions (Maryla, Marita, Marzena, Marlena or Marietta for instance)

awts