The ability to use a plus icon to add a widget to a content page hasn't been offered to the user. This could be a huge UX issue with users who use laptop trackpads as well as any normally able person if their mouse battery is low.
The problem is the only way to add stuff to the page is drag and drop.
Widget pages allow for the plus icon, what seems to have happened is that the plus icon that was there on the content page editor now seems to be being used as an information icon. On hovering the icon a thumbnail of the fragment is displayed. This is ok, but a plus button would be more useful. As for widgets there are no plus buttons appearing on hover.
Contrast widget pages to content pages.
1) Add a widget page
2) Open the add menu in the control menu
3) Select Applications (Widgets, thingies, bob-bits)
4) hover over the list and see plus icons, click one it adds that to the page without drag/drop
5) Try doing the same on a content page, not possible.
Widgets and Fragments on Content pages to have a plus icon that allows the fragment or thingy or gadget to be added to the page.
The thingys can only be added to the page via drag and drop.