Are you saying it's against the terms of Mac/Apple's EULA?
Yup. According to the EULA from Apple, you agree to only use macOS on an Apple "branded" computer. Some wiseasses put Apple stickers on their computers and argue that it's an Apple "branded" computer. Basically, if you legally purchased the license (had to be from buying an iMac, Mac Mini, or MacBook), and you don't intent to take profit from Apple (you don't do this for anyone else, be it for free or profit) then I see it as you aren't taking money from Apple. I use my wife's MacBook to get the backup from Boot Camp. Personally, I refuse to use their hardware. The computer I did it on was an Acer, and it eventually died from old age. I'm obviously leaving out steps, as to not promote taking money from Apple.
I actually use Windows and Ubuntu for daily work. As I serve as the school's liaison to the district's tech department, I used the Hackintosh to test programs on macOS for teachers. The district's technological infrastructure uses Windows, and the tech department won't help faculty who chooses to their own personal Macs, instead of the district provided Dells.