For one thing, it is a major change from how previous versions of Windows has worked. It looks more like a tablet user interface (or UI), something that's OK if you're using a tablet or a laptop with a touchscreen. But for desktops and traditional laptops it isn't very friendly or useful.
I've had more than a little experience with Windows 8 with my first exposure coming when I helped configure Horse Girl's father's's new laptop. It took me quite some time to figure out how to make the desktop look more like the 'old' UI. Like me, he was used to the Windows XP and Windows 7 interface. It was easy to figure out where everything can be found. That's not so of the Windows 8 desktop.
I believe I've written about user interfaces before, particularly dealing with Microsoft Office. When Microsoft changed the user interface for the various Office apps, they got away from the familiar one everyone was used to and changed over to 'ribbons'. That it took experienced users a long time to figure out where all of the familiar toolbars and functions were now residing proved to me that the new design was a failure. It's one thing if the redesign made things easier, but it didn't. In fact, it made it more difficult to do some things, yet another indication that the new user interface was a failure.
The new Windows 8 interface suffers from the same problem. Supposedly Microsoft is working on Windows 8.1 to address these issues, but it brings to mind that Microsoft is trying to force people into using an interface they don't like. As one user commented about the new interface:
People just don't get it. They don't know what's good for them. They're dumb. And they just want to complain. That sums up most of what Windows 8 advocates and even Microsoft says about people who simply don't WANT to use this OS. Look, this is really very simple. If you make a car no one wants to drive you had better go back and make something else if you want to stay in the car business. You don't complain that no one wants to buy your car and you don't blame them for poor design. The market is going to buy what it wants. You can make that and profit or make what you want and shoot for a niche.I know when it comes time to replace my wife's computer I'm going to do my best to make sure it has Windows 7 installed. The last thing I want to do is spend a boatload of time trying to help her figure out the Windows 8 interface. Both she and I have better things to do with our time.
Maybe it's time for Microsoft to get a clue.