Yes, that it how it is supposed to look.
That area on either side is not wasted. It’s there to keep the content area to a reasonable width on very large monitors. Without that, the content would spread across the screen and that is very difficult to read on a very wide monitor.
You can adjust the width of the center content area within some reasonable parameters by going to Graphene Options >> Display Options >> Column Width.
Keep in mind that if you set it too wide, people with narrow monitors will not be able to see all your content without horizontal scrolling.