First, a disclaimer. I have 12.04 on my home LT and I love it. That being said, I don't think it is "one of the most efficient desktops on the market." Why? Because of the exact reason you listed: you are required to search for most things!
The problem with any search feature is that you have to know what the person who designed the search wants to call whatever it is your looking for. Being a Cross-Platform User I understand how confusing that can be. A perfect example is the one you used, Libre. Many times I have had to open the "All Installed" feature of Unity and scroll through the list of all the programs in order to find the one with an icon that looks like a document because I can't remember that the Ubuntu word processor is called Libre. My point is that it is hard to remember the names of seldom used programs and features in order to search for them. Commonly used programs will be put on the launch bar and not need to be searched for.
For you to say that remembering a title and typing it in is easier than a few clicks is simply saying that you prefer command line to GUI. For you, it may be easier. For most folks, it won't be. Joe Averageuser doesn't want to move his/her hands from the mouse to the keyboard every time they want to accomplish something.
Ubuntu is making huge strides to integrate Linux into the mainstream. One of the main ways they are doing this is realizing that the majority of people prefer to have visual clues about what they are doing. Apple realized this 25+ years ago, MS 15+ years ago. Most Linux distros have GUIs that are on the level of Windows 3.1. It's about time a distro realized that most people care more about ease of use than effectiveness. Keep up the good work Ubuntu!
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