Note: This Idea was moved from a comment on a related thread.
It would be better if there was a way to add some layers in the visible state and some in the invisible state instead of one global switch. This would also help when pulling together data from the catalog to be placed in the map.
Some layers I already know I want to show in the map, some should be disabled, since I only need them later on in the process, but don´t want them to show.
This could be implemented via additional sub-menu in the context menu:

and/or via key when using drag-and-drop:
Catalog -> drag+holdshift and drop in Contents
(The shortcut should always negate the global setting for the selected elements)
or another option: a way to pre-select which layers should be added in visible/invisible state via checkbox and "bulk adding"