What’s wrong with the Start Menu?
It’s a lazy design meant for the days when people would only install a few applications. In 2009, people install dozens if not hundreds of applications, so its concept of using a list view of folders which requires the user to read through a long block of text is archaic. A better design would be to create a sort of “Applications” button in the taskbar which would then pop up a view similar to OS X’s Stacks grid view, where the user is presented with an array of large icons. Visual association is more intuitive than a list view of text.
The Start menu also means that the Windows interface itself is centered around a descending hierarchy of menus. If you want to perform any configuration or alteration to the system settings, you generally have to go through the Start menu, and about 15 other submenus before you arrive at the setting you want. These submenus are navigated primarily through the reading of text rather than large icons which plainly convey the option they represent. (The Control Panel has semi-large icons, but their meanings are not plainly obvious.) In an era of high-resolution displays, Windows’ stubborn reliance on text explanation rather than visual cues is going to cause even more headaches, literal and figurative.
Windows 7 at least fixes taskbar clutter through menu grouping centered around large icons in the taskbar, but it’s like putting a bandage on a cannon shell wound.