Funny thing is Windows accepts forward slashes as arguments in programs and API for long time. They just refuse to return forward slashes and don't give users/developer options to do so, so we have to deal with it anyway
Old Mac OS before Mac OS X used : as path separator Macintosh HD:Users:yourUserName:Desktop:My File.txt. It’s still used for AppleScript. Converting from and to POSIX paths using / happens pretty regularly when writing AppleScript nowadays.
That’s also the reason why : is still an illegal character to use for file names on macOS.
I've never met anyone who likes the windows shell environment, or uses it by choice. Only people who try very hard to convince themselves UNIX is somehow worse.