The dummy content will set the Frontpage to use whats called a Dynamic Template. If you go to Angular>Template Builder and click on Frontpage you will see the elements that are used to build this page.
On the actual "Welcome!" page, there is a setting for using a Dynamic Template on the right hand side. Its set to use the Frontpage template and so will not display any of the content entered into the visual editor.
You can change this so that it uses the content in the visual editor, or continue to edit the page using the Template Builder and the Frontpage template.