Why? I know it's simple to restore but if Microsoft couldn't get that detail right, who knows what else they might have broken under the hood. It's the sort of thing that makes me want to reformat. But I'd still reinstall with Windows 10 because Windows 7 is no longer supported and Windows 8 will no longer have support in a few months. Similarly, software developers are now mostly working in a Windows 10 environment which means higher compatibility and lower risk for end users using Windows 10.
It's not all bad. With Windows 10, when I click on a file and press delete, it no longer asks whether I really want to send the file to the Recycle Bin. I can also have variable window sizes and have Windows automatically resize another window to fit the remaining desktop space. I'm sure those were possible in previous versions, but any improvement to default behavior is welcome. There's also DirectX 12, but by the time that becomes relevant, there will probably be a new version of Windows out.
Does that outweigh the increased telemetry and obnoxious update behavior of Windows 10? Privacy and a predictable user experience are important to me so if Microsoft - and Google - continue as they have been, I'm seeing Linux and Blackberry in my future.
The computing environment when I was growing up was basically: programs do not do anything without your permission. Rebooting my computer without my permission and sending info about how I write to the oh-so secure and reliable cloud is something that used to be called malware.