Customizable "Under Construction" Page

When strikingly sites are under construction, it literally just says those words and that if you own it you can publish it in the editor. Why not make it customizable with a photo in the background and you add your own text when its down. For example " Were just updating a few things, sign up below to receive an email when its back up" Its looks very unappealing, and that would just be better for business if it can be changed.