It's been two years now since Canonical made Unity the default desktop environment in Ubuntu. Since the release of Ubuntu 11.04 Natty Narwhal the distribution has seen some interesting times, as a backlash against the new desktop led to much dissent in the Linux community. (See Ubuntu 12.10 Quantal Quetzal review.)
Some accused the company of wanting to be too much like Apple, with its heavy-handed control over design and functionality. Others were just mystified at the loss of customisation that previous versions of Ubuntu had made so easy and couldn't understand why Unity, which had been designed for netbooks, was being forced onto their large-screen desktops.
Many users jumped ship, with Ubuntu-based distributions such as Linux Mint (which retained a more familiar GNOME environment) growing in popularity as a result.
rest here