What you propose is rewriting GladeXML but using perl instead of xml for interface description.

          <child>
            <widget class="GtkTextView" id="text1">
              <property name="visible">True</property>
              <property name="can_focus">True</property>
              <property name="editable">True</property>
              <property name="justification">GTK_JUSTIFY_LEFT</propert
+y>
              <property name="wrap_mode">GTK_WRAP_WORD</property>
              <property name="cursor_visible">True</property>
            </widget>
          </child>
[download]

$parent->TextView(
    Name => "text1",
    -visible => 1,
    -editable => 1,
    -justification => "left",
    -wrap_mode => "word",
    -cursor_visible => 1,
);
[download]

And where are those tools that would allow drawing GUI with your proprietary perl interface?

The advantage lies in the fact that only perl can parse Perl.

Makeshifts last the longest.