I recall being mildly shocked when Windows 95 came out with the the [x] button. I don't know why, but I thought that it was somewhat dangerous to allow users to quickly exit an application like this. Maybe it's because I was used to Windows 3.11, where you had to actually double-click the [-] button to exit an application.
Agreed. But more to the point, I'd like to know what idiot decided it would be great to put a close button right next to the maximise and minimise buttons. It's a disaster just waiting for a mis-click. Since Win95, everyone else has copied this particular feature. First thing I do whenever I do a new Linux install is put the close button on its own on the left where it belongs.
Plus, you can maximise/restore by double-clicking the titlebar which is a larger target and I expect most users learn that and almost never touch the actual button.