People walking around with smartphones just don't think of themselves as "users of software," though that's exactly what they are.
It's unclear wording. It's also not the most immediate and intuitive concept for people outside the industry to wrap their heads around.
Think about driving a car. You're driving a car, you need to know about stuff like having a license and gas and insurance and so on, i.e. the things that a "driver" or "motorist" is generally responsible for.
Obviously, no license needed for having a smartphone, and all you really need is a charger to keep it going, which is part of why there's nothing nudging people to that conceptual leap of being "a user of software".
We could do better, but there's an industry-wide revulsion to finding the right language for communicating with your people, i.e. marketing.
I used to be a big advocate of "free software" as distinct from "open source," but after spending a few years in the marketing side of the industry, I don't give a shit at all about that distinction, because neither does anyone who isn't already drowning in the kool aid.
Like I said, we could do better.