I prefer Windows 7 to Windows 10. My mom upgraded to 10 and her label printer that she needs for her job (she ships stuff) stopped working. The drivers were incompatible with 10.
I'm not sure if that is Windows fault, or poor coding on the driver's part. I'm afraid of updating because I'm afraid that some of my programs will become incompatible. My mom also sometimes needs help with her computer, and I couldn't help her if I was still on 7 and she was on 10.
I think I'm a bit nostalgic towards Windows XP, because it was the first OS on the first computer I've ever owned. Windows 7 is pretty similar to XP, so that is probably a big factor as well.