The application launcher is too cluttered. The screenshot below uses a theme to accentuates the problem, but whether one presents 54 or 24 icons at once to the user, it's still too much.
Though it echoes the launcher found in the iOS and Android, it isn't really much better than the joke about the cluttered Windows desktop.
Most users only call upon a small subset of the applications installed on their system. By having the launcher present the user with a set of "most frequently used" and "last used" applications, it will cut down the amount of time spent pixel hunting. More experienced users might know program names offhand and use the search functionality, but that's not necessarily true of novice users.
As an aside, the "Featured" bin at the top provides the description of a randomly installed application on the system. This is oriented towards novice users; more experienced users might favour replacing it with a "recent documents" bin or whatnot.
UnsolvedCypher: I believe this has been implemented in 3.8. Should this page be deleted?