This is related to https://issues.alfresco.com/jira/browse/ACE-3156, which has been closed as not a bug with the comment:
" This is not a bug as this is not a translated item, it is the name of a page.
Users can rename the "Main Page" to something more meaningful to their site as they see fit. "
This implies having to change the files below:
Plus they would have to do the same for every upgrade.