I hear a lot of users stating that their reason for not wanting to upgrade from Windows 7 is due to Microsoft's spying, There is a lot of confusion between telemetry and spying. telemetry is an essential part of any complex system, which any operating system must be classed as.
Microsoft has instigated a vast Beta Test program where users volunteer to provide detailed manual feedback to aid in improvement of the OS before the official release, this is extended to small amounts of feedback from the release version to fine tune the OS to work with all the variations that are actually used in the real world. Unlike companies such as Apple that tightly controls the hardware and software so that the variations are minimal between systems and so the testing can be more easily performed.
The whole Windows / PC ecosystem is so many times larger than Apple's (not including iPhone), where a Windows OS is expected to work flawlessly with any variation of hardware and software, that issues are certain to appear after release of the OS when it is used on a combination of hardware and software that is unique. This is where Telemetry is used to fine tune the system.
Telemetry is basically a small amount of data that is captured and used to tune a system. This can be data captured during a failure of the system which helps to prevent the issue causing problems in future, or it can be data from the correct operation of component parts working together (this is normally just of use where an unusual situation is in place, a rare combination or setup). Telemetry has no need to be identifiable to a person, (indeed this would actually reduce the value of the data as it would increase the amount of data transmitted without any extra usable information).
Microsoft does give some options to turn off Telemetry so that will allow a user to control data transfer. The issue is more serious with the home version of Windows 10 where a lot of control has been removed, (the vast majority of users of the Home versions would never even think about changing settings). There are other versions of the OS that are designed for more advanced users and enthusiasts that does allow a lot more control.
Telemetry is an essential part of the world we live in - would anyone demand that the black box and fly-by-wire systems on the aircraft they are boarding be switched off as it may contain their personal Lunch menu? I doubt it