thanks esmi. after reading that page, my impression is that the wp developers hardcoded hyperlinked comment dates in order to provide permalinks to comments.
reasonable enough. perhaps I should simply style the link so it doesn't look like a link.
for those who *really* don't want hyperlinked comment dates, line 1362 to line 1637 of wp-includes/comment-template.php can be modified to this:
<div class="comment-meta commentmetadata">
<?php printf( __('%1$s at %2$s'), get_comment_date(), get_comment_time()) ?>
<?php edit_comment_link(__('Edit'),' ','' ); ?>
which removes the following line of code:
<a href="<?php //echo htmlspecialchars( get_comment_link( $comment->comment_ID ) ) ?>">
along with the closing
</a> in the following line.
this will prevent comment dates from being hyperlinked.