'widget_text' filter is ambigous

Apparently, the only widget that uses the ‘widget_text’ filter is the “WP_Widget_Text” widget. This is documented, but very easy to miss. I’ve spent nearly an hour before delving through the wordpress code, and even then I thought it was a bug.

Since ‘text_title’ is used by all widgets, why isn’t there a matching ‘widget_content’? Even worse, there’s a seemingly appropriate ‘widget_text’ that’s specific to a single widget type.