Since GNOME 3.8 eliminated "subcategories" for a more flat layout of the stuff in the activities menu I don't know what the right term is to use here. When I say "subcategories" I'm referring to things like "Sundry" and "Utilities".

Anyway as a bit of a background I do most things with the keyboard and am a heavy user of keyboard shortcuts.

Anyway say I'm in the Applications area and looking around for something. Most things I can reach with the keyboard but not anything that's in a subcategory. Say I arrow my way over to Utilities and hit enter. The popup with application choices shows up but I can't select a specific item there with the keyboard. If anything when I use the arrow keys the selector is moving around between the apps behind that in the background.

Please fix this.

One possibility is to let users navigate that popup menu with arrows.

Another is to establish a completely flat app hierarchy. Clearly removing application categories in favor of a flatter layout was a good idea as oftentimes an app may logically fall into one of several categories and it's unclear where to put it. However instead of removing categories completely GNOME 3.8 has settled on this awkward inconsistent illogical compromise that doesn't make any sense. My advice is to finish what was started and completely flatten the applications area.

Like as I said before this categorizing has problems with where to put an app anyway. And GNOME's type to dynamically search and launch is quite good. I don't need categories to find what I'm looking for. Say I don't know that my web browser is called Firefox. Guess what it's not a problem. If I type something like "web" or "browser" Firefox still shows up in the results and is the default highlighted/pointed to result.

In conclusion for what little it's worth my advice is to completely finish what you started and flatten the application hierarchy.