Why don't Django and AngularJS follow their MVC patterns when implementing widgets/directives?

Django and Angular follow MVC (this way or another..) patterns, and therefore should separate HTML from code-behind.

But when browsing Django source code you can easily find:

class ClearableFileInput(FileInput):
    ....

    template_with_initial = u'%(initial_text)s: %(initial)s %(clear_template)s<br />%(input_text)s: %(input)s'

    template_with_clear = u'%(clear)s <label for="%(clear_checkbox_id)s">%(clear_checkbox_label)s</label>'

Instead of write a template and render it with Context.

or

def as_table(self):
    "Returns this form rendered as HTML <tr>s -- excluding the <table></table>."
    return self._html_output(
        normal_row = u'<tr%(html_class_attr)s><th>%(label)s</th><td>%(errors)s%(field)s%(help_text)s</td></tr>',
        error_row = u'<tr><td colspan="2">%s</td></tr>',
        row_ender = u'</td></tr>',
        help_text_html = u'<br /><span class="helptext">%s</span>',
        errors_on_separate_row = False)

Instead of using templatetags, or use an external template.

Same with AngularJS, in their samples on the homepage you find:

  this.addPane = function(pane) {
          if (panes.length == 0) $scope.select(pane);
          panes.push(pane);
        }
      },
      template:
        '<div class="tabbable">' +
          '<ul class="nav nav-tabs">' +
            '<li ng-repeat="pane in panes" ng-class="{active:pane.selected}">'+
              '<a href="" ng-click="select(pane)">{{pane.title}}</a>' +
            '</li>' +
          '</ul>' +
          '<div class="tab-content" ng-transclude></div>' +
        '</div>',
      replace: true

Instead of just using templateUrl and than write the template in a separate file and not inside the code.

Is there a good reason for this? or some other reasonable cause?

I myself don't find one, when writing widgets/directives I manage to separate the html from the code and everything works as expected.