I still use Windows 7 myself. After 20 minutes playing with a new Windows 8 PC at Best Buy, I built my new rig with Windows 7. I have always used the start menu. The main reason I would miss it would be that I hate clutter on my desk top. I link short cuts to games and my favorite browser, that's it. The task bar contains links to my internet browsers, Windows Explorer, as well as driver control panels on the right. You can configure the start menu in 7 to save as many recently used programs as you want in it's list, which does not take up the whole screen so you can still see open windows. And also makes your desktop less cluttered. On top of that, I organize any custom made directories into folders with sub folders and use Windows explorer to view them. For example, E: Pics/Projects/Gimp/InProgress. I know ALL pics are in the Pics folder, because I put them there. And I am only a few clicks away from opening my projects which are in the appropriate sub folders inside the Pics folder. This method allows me to view all picture "albums" using only one shortcut, the explorer one, instead of links to every individual thing I do, which would create quite a mess. It also eliminate the ugly folder links on my desktop, which is a pet peeve of mine. If I want to open a program, I just scroll down the All Programs list at the bottom of the start menu and find it in it's folder if it isn't listed as a single executable file there. The control panel, system tools, event viewer, etc., etc., and more etc. are also not in one place where they can easily be found as they are in the start menu. The whole start menu system is much more streamlined and easier to navigate for almost everyone. It's so basic and simple, everything is laid out on a list for you to see. It shows everything you want it to in by far less space. If I had live tiles of everything on my rig, it would take up a lot of room, and take longer to scroll through than a list of words would. Also a word that says, "Photoshop CS6" is impossible to misinterpret where a picture could be misleading. It also scrolls sideways, which feels weird on a PC. There is also the annoyance of closing some programs by swiping them down like on a phone and hot corners or whatever they're called, all things that are not needed if the start menu is there.
The main issue I and many others have is the drastic difference between 7 and 8 when trying to simply navigate through your computer and finding simple tools and less used programs, which has been done basically the same way for about 20 years now, and was suddenly turned upside down. 7 was the pinnacle of the original Windows 95 UI ideas, and many loved the way it looked and felt. You had complete control of what was shown, what was made into a shortcut, and where it all was displayed. Aside from the slight customization of recent programs list and appearance, NOTHING needs to be customized to be useful. A little long winded, but this is the best way I can describe why I hate the whole Metro UI design.