The Start menu is gone, but consider this: the best thing that Microsoft did to the Start menu came in Vista, when the new integrated search made it so that you didn’t actually have to go digging through folders and sub-folders. Not only is that search functionality alive and well in Windows 8, but the problem of folders and subfolders that it was created to avoid is also gone.
Yes, Metro is very different from what came before, and yes, Metro was clearly designed with touch in mind, but once you learn its tricks (and especially once you’ve got the new keyboard shortcuts dedicated to memory) it acquits itself as a flexible and powerful user interface. Even if you’re on a massive 2560x1440 display with multiple monitors and never, ever touch the Windows Store or a Metro app, the Start screen serves as a much more configurable and useful application launcher than the tiny Start menu ever was.
I don’t want to say that the Start screen is definitively better for PC users, especially those who rely on Windows 8's sometimes flaky mouse motions, but I strongly disagree with anyone who says that it’s worse. Microsoft has greatly improved Windows’ functionality on tablets (and if you’ve never used Windows 7 or something older on a currently available tablet PC, let me tell you: it isn’t pretty) while not greatly impacting the operating system’s usability on desktops and laptops. Metro's biggest problem right now is going to be what users bring with them: years of accumulated experience about how Windows should look and work. Windows is still Windows, but all of these changes add up to a new interface that is just different enough to spook users who rely on remembered actions to get around their computers, rather than an actual understanding of how and why things work.