Up until about two weeks ago, I thought people were being unreasonably whinny about the changes in Windows 10.
This was before I noticed that Candy Crush Saga silently installed itself on my Windows 10 machine. Not only that but it was listed as a running application in the Task Manager. Think about it: the system is silently installing & running third party apps without your consent (!) and there's no option to control that behavior. (This is not me having hallucinations, see [1] for other reports of that behavior).
I don't know why it took that long but it seriously compromised any trust I had with the company.
[1] https://www.google.ie/search?rls=en&q=windows+10+candy+crush...