Why doesn't button click event “bubble up visual tree” to StackPanel as MSDN article states?

Question

In the MSDN article Understanding Routed Events and Commands In WPF, it states

an event will bubble (propagate) up the visual tree from the source ele

Answer 1

In addition, if you want the stackpanel to receive the event, change the stackpanel xaml to:

and the event signature to:

private void TheStackPanel_MouseDown(object sender, RoutedEventArgs e)

In this case, the stackpanel will recieve the button's click event. However, clicking on the stackpanel itself won't fire any event, since it listens specifically to a button click.