If you want to have an option at the backend to show or hide this count just follow this:

file mod_k2_tools/tmpl/authors.php

Find:
      <span class="abAuthorCommentsCount">
      	<?php echo $author->latest->numOfComments;?> <?php echo JText::_('comments');?>
      </span>

Replace with:
	<?php if ($params->get('authorCommentsCount')):?>
      <span class="abAuthorCommentsCount">
      	<?php echo $author->latest->numOfComments;?> <?php echo JText::_('comments');?>
      </span>
	<?php endif; ?>

************
File mod_k2_tools/mod_k2_tools.xml

Add this code after line 56 (before <!-- Calendar Settings -->:

	<param name="authorCommentsCount" type="radio" default="1" label="Comments Counter" description="Show authors comments count">
      <option value="0">Hide</option>
      <option value="1">Show</option>
    </param>

********
file mod_k2_tools/helper.php

Find:
	$query = "SELECT COUNT(*) FROM #__k2_comments WHERE published=1 AND itemID={$author->latest->id}";
        $db->setQuery($query);
        $author->latest->numOfComments = $db->loadResult();

Replace with:

       if ($params->get('authorCommentsCount')) {
	$query = "SELECT COUNT(*) FROM #__k2_comments WHERE published=1 AND itemID={$author->latest->id}";
        $db->setQuery($query);
        $author->latest->numOfComments = $db->loadResult();
	   }

If you have your site translated to other language you should add the text to translate.

Hope this help you

Rgds