If I disable "Logo" and only wish to display "site name", it does not show. It leaves an empty tag in the code and the site name header does not get displayed. I tried to self-troubleshoot by looking in page.tpl.php but you do not use Drupal standards to construct the page.tpl.php and therefore non of the markup is in that file.
Currently, Evolve theme does not supports to show Site Name automatically, So please go to layout setting page then remove Logo region then add another region for Site Name. After that please create new block with site name text then assign to the region you created before. We will update Evolve theme for toggle display site name automatically. Thanks!