That said, I think we should not overly subdivide. If the menu depth
gets too large, we will be spending more time clicking menu levels
than scanning a menu list for the app name. For example in my
experience, I may have a couple of astronomy apps, but rarely 50
installed on any one system. I doubt many users will want to click
Apps -> Science -> Astronomy -> Cosmology to get a list containing 1
cosmology program that is installed. Same for other fields of science.
How many of us actually have more than 5-10 apps installed for a given field?