Yup. My "enterprise" (home business) is an air-gapped XP machine, a sometimes connected Win 7 machine and a Linux box for routine web stuff and email. I have a spare Win 7 machine that I will probably try Win 10 on but will mostly leave it off the internet. I want to see what will run on it.
I thought it was a good idea at the time when I bought 3 retail copies of Windows XP on the last day they were available to the public. They have never been installed on a computer and only one has had the package opened. Seems a waste, in retrospect.