If you don't know what GNOME is you have you really shouldn't compare UI's since you have yet to experience GNOME. You probably haven't touched KDE, XFCE, or CDE for that matter. Try them all. Then you'll understand why he says that windows 8 UI is broken. Also he only talks about Windows 8 UI not the other Windows platforms. Your defence of windows is admirable but you really need to read.

Good synchronisation technology does exist... it's called Google.. My phone, mac, windows pc's all share the same data and use SSO. The API allows complete access to your data from any point. Take a look at the google API for gmail, instant upload, social and OAuth. Very extensible, easy to use, and cross platform(available for all types of languages per platform) which gives you greater freedom of platform choice. Google renders the operating environment irrelevant.

Please note I am not talking about A specific google platform such as android, I am talking about googles cloud technology, services, and API.