It’s also that they put out a product I actually find value from like Linux support, Steam Input, forums, workshop, etc. I enjoy using Steam because I find it to be a good experience.
It’s like reasons people prefer Android or Apple even if they share the same apps. Really can’t discount the experience simple things like navigation and social features do to add value. Those who dismiss it as unimportant probably share the same views as some MBA who only looks at the numbers and think they can just enter and corner a market through brute force spending.