It's common for me to go through the menus to see what applications�of a concrete kind�I have installed.
For example: if I have to do some system configuration task, I go through the System menu and read the names of the applications to find the most suitable for my purpose, if there is any.
In Unity, it wasn't obvious for me how to do this. In fact, for a few days I thought that I couldn't. Now I've realised that if I push 'Find more apps' in the dash, in the right of the search bar there is a drop-down menu where I can select the category I want. It wasn't easy to find, at least for me.
I think this categorization is important; having the applications classified gives a feeling of cleanliness and control of your installation that is important for lots of users. It helps you to find easily what applications of a kind you have installed, and helps new users (and some old ones) to find what they want, sometimes better than doing a search.
It wouldn't be hard to do it better; when pressing 'find apps' in the dash, the user would see the search bar, just like now, and below it the different categories. If he clicks a category, all the applications of this category would be displayed. Instead, now Unity shows below the search bar a few applications in alphabetical order, which I think is of little use.