Was not trying to say your assessment was incorrect, but it read like all users have that issue, when that is not the case.
It really depends on the physical ability to turn around and look back. I know too many people who do not have any trouble looking back. I also people who do have trouble.
High back chairs are an impediment to looking back, as are chairs with large side bolsters. The easiest chairs to aid in looking back are low back and swivel.
In this area, it is easy for a user to test before buying. Just sit in your chair, grab your joystick, and if you cannot turn to look directly behind you without a lot of issues, then you are probably going to have to use the key combination to look back.